{"product_id":"simple-interest-calculator","title":"Simple Interest Calculator","description":"\u003cstyle\u003e\n.sic-calculator {\n  --ink: #0f172a;\n  --muted: #475569;\n  --border: #e2e8f0;\n  --surface: #ffffff;\n  --tint: #f8fafc;\n  --primary: #1d4ed8;\n  --accent: #c2410c;\n  --accent-hover: #9a3412;\n  --chart-1: #1e40af;\n  --chart-2: #0d9488;\n  --chart-3: #7c3aed;\n  --chart-4: #be185d;\n  --chart-5: #334155;\n  color: var(--ink);\n  container-type: inline-size;\n  background: var(--surface);\n  border: 1px solid var(--border);\n  border-radius: 8px;\n  box-shadow: 0 1px 2px rgba(15,23,42,.06);\n  font-family: -apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, Helvetica, Arial, sans-serif;\n  font-size: 15px;\n  line-height: 1.55;\n  margin: 0 auto;\n  max-width: 1200px;\n  overflow-wrap: anywhere;\n  padding: 24px;\n  width: 100%;\n}\n.sic-calculator,\n.sic-calculator *,\n.sic-calculator *::before,\n.sic-calculator *::after {\n  box-sizing: border-box;\n}\n.sic-calculator * {\n  min-width: 0;\n}\n.sic-calculator h2,\n.sic-calculator h3,\n.sic-calculator p {\n  margin-top: 0;\n}\n.sic-calculator h2 {\n  font-size: 24px;\n  font-weight: 700;\n  line-height: 1.25;\n  margin-bottom: 8px;\n}\n.sic-calculator h3 {\n  font-size: 18px;\n  font-weight: 650;\n  line-height: 1.35;\n  margin-bottom: 12px;\n}\n.sic-calculator a {\n  color: var(--primary);\n  font-weight: 600;\n  text-decoration-thickness: 1px;\n  text-underline-offset: 2px;\n}\n.sic-calculator a:hover {\n  text-decoration-thickness: 2px;\n}\n.sic-calculator button,\n.sic-calculator input,\n.sic-calculator select {\n  font: inherit;\n}\n.sic-calculator button,\n.sic-calculator input,\n.sic-calculator select {\n  min-height: 44px;\n}\n.sic-calculator button,\n.sic-calculator select {\n  cursor: pointer;\n}\n.sic-calculator :focus-visible {\n  outline: 3px solid var(--primary);\n  outline-offset: 2px;\n}\n.sic-header {\n  border-bottom: 1px solid var(--border);\n  padding-bottom: 16px;\n}\n.sic-subtitle {\n  color: var(--muted);\n  margin-bottom: 12px;\n  max-width: 760px;\n}\n.sic-pills {\n  display: flex;\n  flex-wrap: wrap;\n  gap: 8px;\n}\n.sic-pill {\n  align-items: center;\n  background: var(--tint);\n  border: 1px solid var(--border);\n  border-radius: 999px;\n  color: var(--muted);\n  display: inline-flex;\n  font-size: 13px;\n  font-weight: 600;\n  gap: 6px;\n  line-height: 1.35;\n  padding: 6px 10px;\n  white-space: nowrap;\n}\n.sic-pill strong {\n  color: var(--ink);\n  font-variant-numeric: tabular-nums;\n}\n.sic-toolbar {\n  display: flex;\n  flex-wrap: wrap;\n  gap: 12px;\n  padding: 16px 0;\n}\n.sic-button {\n  align-items: center;\n  border: 1px solid transparent;\n  border-radius: 6px;\n  display: inline-flex;\n  font-size: 15px;\n  font-weight: 700;\n  gap: 10px;\n  justify-content: center;\n  line-height: 1.2;\n  padding: 12px 18px;\n  text-align: center;\n  text-decoration: none;\n  white-space: nowrap;\n}\n.sic-button-primary {\n  background: var(--accent);\n  color: #ffffff;\n  box-shadow: 0 1px 2px rgba(15,23,42,.12);\n}\n.sic-button-primary:hover {\n  background: var(--accent-hover);\n  box-shadow: 0 2px 4px rgba(15,23,42,.18);\n}\n.sic-button-secondary {\n  background: var(--surface);\n  border-color: #64748b;\n  color: var(--ink);\n}\n.sic-button-secondary:hover {\n  background: var(--tint);\n  border-color: #64748b;\n}\n.sic-button-icon {\n  display: inline-flex;\n  height: 20px;\n  width: 20px;\n}\n.sic-button-icon svg {\n  display: block;\n  height: 100%;\n  width: 100%;\n}\n.sic-workspace {\n  display: grid;\n  gap: 24px;\n  grid-template-columns: minmax(0, 1fr);\n}\n.sic-panel,\n.sic-card {\n  background: var(--surface);\n  border: 1px solid var(--border);\n  border-radius: 8px;\n  box-shadow: 0 1px 2px rgba(15,23,42,.04);\n  padding: 20px;\n}\n.sic-input-panel {\n  container-type: inline-size;\n}\n.sic-panel-intro {\n  color: var(--muted);\n  margin-bottom: 16px;\n}\n.sic-solve-fieldset {\n  border: 0;\n  margin: 0 0 20px;\n  padding: 0;\n}\n.sic-solve-fieldset legend {\n  font-size: 14px;\n  font-weight: 700;\n  margin-bottom: 8px;\n}\n.sic-segments {\n  display: grid;\n  gap: 4px;\n  grid-template-columns: repeat(4, minmax(0, 1fr));\n}\n.sic-segment-input {\n  clip: rect(0 0 0 0);\n  clip-path: inset(50%);\n  height: 1px;\n  opacity: 0;\n  pointer-events: none;\n  position: absolute;\n  width: 1px;\n}\n.sic-segment-label {\n  align-items: center;\n  background: var(--tint);\n  border: 1px solid var(--border);\n  border-radius: 6px;\n  color: var(--muted);\n  cursor: pointer;\n  display: flex;\n  font-size: 13px;\n  font-weight: 700;\n  justify-content: center;\n  min-height: 44px;\n  padding: 8px;\n  text-align: center;\n}\n.sic-segment-input:checked + .sic-segment-label {\n  background: #eff6ff;\n  border-color: var(--primary);\n  color: #1e3a8a;\n  box-shadow: inset 0 0 0 1px var(--primary);\n}\n.sic-segment-input:focus-visible + .sic-segment-label {\n  outline: 3px solid var(--primary);\n  outline-offset: 2px;\n}\n.sic-fields {\n  display: grid;\n  gap: 16px;\n  grid-template-columns: minmax(0, 1fr);\n}\n@container (min-width: 460px) {\n  .sic-input-panel .sic-fields {\n    grid-template-columns: repeat(2, minmax(0, 1fr));\n  }\n}\n.sic-field {\n  display: flex;\n  flex-direction: column;\n  gap: 6px;\n}\n.sic-label {\n  color: var(--ink);\n  font-size: 14px;\n  font-weight: 600;\n  line-height: 1.35;\n}\n.sic-control-row {\n  align-items: stretch;\n  display: grid;\n  gap: 8px;\n  grid-template-columns: minmax(0, 1fr) minmax(112px, auto);\n}\n.sic-input,\n.sic-select {\n  background: var(--surface);\n  border: 1px solid #64748b;\n  border-radius: 6px;\n  color: var(--ink);\n  font-size: 15px;\n  line-height: 1.2;\n  padding: 10px 12px;\n  width: 100%;\n}\n.sic-input {\n  font-variant-numeric: tabular-nums;\n}\n.sic-input[readonly] {\n  background: #eff6ff;\n  border-color: #93c5fd;\n  color: #1e3a8a;\n  cursor: default;\n  font-weight: 700;\n}\n.sic-input[aria-invalid=\"true\"] {\n  border-color: #b91c1c;\n  box-shadow: 0 0 0 1px #b91c1c;\n}\n.sic-helper {\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n  line-height: 1.4;\n  min-height: 37px;\n}\n.sic-error {\n  color: #991b1b;\n  display: none;\n  font-size: 13px;\n  font-weight: 600;\n  line-height: 1.4;\n  min-height: 18px;\n}\n.sic-error.sic-visible {\n  display: block;\n}\n.sic-form-note {\n  background: var(--tint);\n  border: 1px solid var(--border);\n  border-radius: 6px;\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n  margin-top: 16px;\n  padding: 10px 12px;\n}\n.sic-results {\n  align-self: start;\n  display: flex;\n  flex-direction: column;\n  gap: 16px;\n}\n.sic-primary-result {\n  background: #eff6ff;\n  border: 1px solid #bfdbfe;\n  border-radius: 8px;\n  padding: 20px;\n}\n.sic-result-eyebrow {\n  color: #1e3a8a;\n  font-size: 13px;\n  font-weight: 700;\n  letter-spacing: .04em;\n  margin-bottom: 4px;\n  text-transform: uppercase;\n}\n.sic-result-value {\n  color: var(--ink);\n  font-size: 30px;\n  font-variant-numeric: tabular-nums;\n  font-weight: 700;\n  line-height: 1.2;\n  overflow-wrap: anywhere;\n}\n.sic-result-summary {\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n  margin-top: 8px;\n}\n.sic-result-grid {\n  display: grid;\n  gap: 12px;\n  grid-template-columns: repeat(2, minmax(0, 1fr));\n}\n.sic-metric {\n  background: var(--tint);\n  border: 1px solid var(--border);\n  border-radius: 6px;\n  padding: 14px;\n}\n.sic-metric-label {\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 600;\n  line-height: 1.35;\n  margin-bottom: 4px;\n}\n.sic-metric-value {\n  color: var(--ink);\n  font-size: 20px;\n  font-variant-numeric: tabular-nums;\n  font-weight: 700;\n  line-height: 1.25;\n  overflow-wrap: anywhere;\n}\n.sic-formula {\n  background: var(--surface);\n  border-left: 4px solid var(--primary);\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n  padding: 8px 12px;\n}\n.sic-formula strong {\n  color: var(--ink);\n}\n.sic-section {\n  margin-top: 24px;\n}\n.sic-section-heading {\n  align-items: end;\n  display: flex;\n  flex-wrap: wrap;\n  gap: 8px 16px;\n  justify-content: space-between;\n  margin-bottom: 12px;\n}\n.sic-section-heading h3 {\n  margin-bottom: 0;\n}\n.sic-section-copy {\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n  margin: 0;\n}\n.sic-breakdown-grid {\n  display: grid;\n  gap: 24px;\n  grid-template-columns: minmax(0, 1fr);\n}\n.sic-chart-card {\n  container-type: inline-size;\n  display: flex;\n  flex-direction: column;\n  gap: 16px;\n}\n.sic-chart-card.sic-safe-stack {\n  gap: 20px;\n  height: auto;\n}\n.sic-chart-title-row {\n  display: flex;\n  flex-direction: column;\n  gap: 4px;\n}\n.sic-chart-total {\n  color: var(--ink);\n  font-size: 20px;\n  font-variant-numeric: tabular-nums;\n  font-weight: 700;\n}\n.sic-chart-interpretation {\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n}\n.sic-chart-cluster {\n  align-items: center;\n  display: grid;\n  gap: 20px;\n  grid-template-columns: minmax(0, 1fr);\n  justify-items: center;\n}\n.sic-plot {\n  align-items: center;\n  display: flex;\n  justify-content: center;\n  max-width: 100%;\n  width: 100%;\n}\n.sic-donut-plot {\n  max-width: 320px;\n}\n.sic-line-plot {\n  max-width: 760px;\n}\n.sic-plot svg {\n  display: block;\n  height: auto;\n  max-width: 100%;\n  overflow: visible;\n  width: 100%;\n}\n.sic-legend {\n  display: grid;\n  gap: 10px;\n  justify-content: center;\n  max-width: 100%;\n}\n.sic-legend-row {\n  align-items: baseline;\n  display: grid;\n  column-gap: 10px;\n  grid-template-columns: 14px minmax(78px, auto) auto auto;\n  justify-content: start;\n  row-gap: 4px;\n}\n.sic-legend-swatch {\n  border-radius: 3px;\n  display: inline-block;\n  height: 12px;\n  width: 12px;\n}\n.sic-legend-label,\n.sic-legend-value,\n.sic-legend-percent {\n  font-size: 13px;\n  font-weight: 600;\n  line-height: 1.35;\n}\n.sic-legend-label {\n  color: var(--ink);\n}\n.sic-legend-value,\n.sic-legend-percent {\n  color: var(--muted);\n  font-variant-numeric: tabular-nums;\n  white-space: nowrap;\n}\n.sic-chart-callout,\n.sic-table-note {\n  background: var(--tint);\n  border: 1px solid var(--border);\n  border-radius: 6px;\n  color: var(--muted);\n  font-size: 13px;\n  font-weight: 500;\n  line-height: 1.5;\n  margin-top: 16px;\n  padding: 10px 12px;\n}\n.sic-chart-empty {\n  align-items: center;\n  background: var(--tint);\n  border: 1px dashed #64748b;\n  border-radius: 6px;\n  color: var(--muted);\n  display: none;\n  font-size: 13px;\n  font-weight: 600;\n  justify-content: center;\n  min-height: 88px;\n  padding: 16px;\n  text-align: center;\n  width: 100%;\n}\n.sic-chart-empty.sic-visible {\n  display: flex;\n}\n.sic-data-summary {\n  margin-top: 0;\n}\n.sic-table-controls {\n  align-items: end;\n  display: flex;\n  flex-wrap: wrap;\n  gap: 12px;\n}\n.sic-table-control {\n  display: flex;\n  flex-direction: column;\n  gap: 6px;\n  min-width: 190px;\n}\n.sic-table-wrap {\n  border: 1px solid var(--border);\n  border-radius: 6px;\n  overflow-x: auto;\n  width: 100%;\n}\n.sic-table {\n  border-collapse: collapse;\n  min-width: 620px;\n  width: 100%;\n}\n.sic-breakdown-table {\n  min-width: 360px;\n}\n.sic-chart-summary-table {\n  min-width: 480px;\n}\n.sic-table th,\n.sic-table td {\n  border-bottom: 1px solid var(--border);\n  padding: 10px 12px;\n  text-align: left;\n  vertical-align: top;\n}\n.sic-table th {\n  background: var(--ink);\n  color: #ffffff;\n  font-size: 13px;\n  font-weight: 700;\n  white-space: nowrap;\n}\n.sic-table td {\n  color: var(--ink);\n  font-size: 13px;\n  font-weight: 500;\n}\n.sic-table td.sic-num,\n.sic-table th.sic-num {\n  font-variant-numeric: tabular-nums;\n  text-align: right;\n  white-space: nowrap;\n}\n.sic-table tbody tr:last-child td {\n  border-bottom: 0;\n  font-weight: 700;\n}\n.sic-table tbody tr:nth-child(even) td {\n  background: var(--tint);\n}\n.sic-safe-table-stack .sic-table-wrap {\n  height: auto;\n}\n.sic-safe-table-stack .sic-table-note {\n  margin-top: 20px;\n}\n.sic-education {\n  border-top: 1px solid var(--border);\n  margin-top: 32px;\n  padding-top: 24px;\n}\n.sic-education-grid {\n  display: grid;\n  gap: 24px;\n  grid-template-columns: minmax(0, 1fr);\n}\n.sic-education-section {\n  max-width: 850px;\n}\n.sic-education-section p,\n.sic-education-section li {\n  color: #334155;\n}\n.sic-education-section ul {\n  margin: 0 0 16px;\n  padding-left: 22px;\n}\n.sic-education-section li + li {\n  margin-top: 8px;\n}\n.sic-equation {\n  background: var(--tint);\n  border: 1px solid var(--border);\n  border-radius: 6px;\n  color: var(--ink);\n  font-size: 18px;\n  font-variant-numeric: tabular-nums;\n  font-weight: 700;\n  margin: 16px 0;\n  padding: 14px 16px;\n  text-align: center;\n}\n.sic-visually-hidden {\n  clip: rect(0 0 0 0);\n  clip-path: inset(50%);\n  height: 1px;\n  overflow: hidden;\n  position: absolute;\n  white-space: nowrap;\n  width: 1px;\n}\n@container (min-width: 520px) {\n  .sic-breakdown-card .sic-chart-cluster {\n    grid-template-columns: minmax(240px, 320px) max-content;\n    justify-content: center;\n  }\n}\n@container (min-width: 760px) {\n  .sic-breakdown-grid {\n    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);\n  }\n}\n@container (min-width: 900px) {\n  .sic-workspace {\n    grid-template-columns: minmax(0, .95fr) minmax(0, 1.05fr);\n  }\n}\n@media (max-width: 639px) {\n  .sic-calculator {\n    padding: 16px;\n  }\n}\n@container (max-width: 639px) {\n  .sic-panel,\n  .sic-card {\n    padding: 16px;\n  }\n  .sic-fields,\n  .sic-result-grid {\n    grid-template-columns: minmax(0, 1fr);\n  }\n  .sic-segments {\n    grid-template-columns: repeat(2, minmax(0, 1fr));\n  }\n  .sic-chart-cluster {\n    grid-template-columns: minmax(0, 1fr);\n    row-gap: 16px;\n  }\n  .sic-legend-row {\n    grid-template-columns: 14px minmax(70px, auto) auto auto;\n  }\n}\n@media (max-width: 420px) {\n  .sic-calculator {\n    padding: 12px;\n  }\n}\n@container (max-width: 420px) {\n  .sic-toolbar {\n    align-items: stretch;\n    flex-direction: column;\n  }\n  .sic-button {\n    width: 100%;\n  }\n  .sic-control-row {\n    grid-template-columns: minmax(0, 1fr);\n  }\n  .sic-table-control {\n    width: 100%;\n  }\n  .sic-legend-row {\n    grid-template-columns: 14px minmax(0, 1fr) auto;\n  }\n  .sic-legend-percent {\n    grid-column: 2 \/ 4;\n    padding-left: 0;\n  }\n}\n\u003c\/style\u003e\n\u003cdiv class=\"sic-calculator\" data-calculator-root\u003e\n  \u003cheader class=\"sic-header\"\u003e\n    \u003ch2\u003eSimple Interest Calculator\u003c\/h2\u003e\n    \u003cp class=\"sic-subtitle\"\u003eSolve for end balance, principal, term, or rate, then review the full interest breakdown, accumulation chart, and period-by-period schedule.\u003c\/p\u003e\n    \u003cdiv class=\"sic-pills\" aria-label=\"Live calculation highlights\"\u003e\n      \u003cspan class=\"sic-pill\"\u003eSolved value \u003cstrong class=\"sic-pill-solved\"\u003e$26,000.00\u003c\/strong\u003e\u003c\/span\u003e\n      \u003cspan class=\"sic-pill\"\u003eTotal interest \u003cstrong class=\"sic-pill-interest\"\u003e$6,000.00\u003c\/strong\u003e\u003c\/span\u003e\n      \u003cspan class=\"sic-pill\"\u003eTerm \u003cstrong class=\"sic-pill-term\"\u003e10 years\u003c\/strong\u003e\u003c\/span\u003e\n      \u003cspan class=\"sic-pill\"\u003eAnnual rate \u003cstrong class=\"sic-pill-rate\"\u003e3.00%\u003c\/strong\u003e\u003c\/span\u003e\n    \u003c\/div\u003e\n  \u003c\/header\u003e\n\n  \u003cdiv class=\"sic-toolbar\" aria-label=\"Calculator actions\"\u003e\n    \u003cbutton class=\"sic-button sic-button-primary sic-download\" type=\"button\"\u003e\n      \u003cspan class=\"sic-button-icon\" aria-hidden=\"true\"\u003e\n        \u003csvg viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"\u003e\n          \u003cpath d=\"M12 3v12\"\u003e\u003c\/path\u003e\n          \u003cpath d=\"m7 10 5 5 5-5\"\u003e\u003c\/path\u003e\n          \u003cpath d=\"M5 21h14\"\u003e\u003c\/path\u003e\n        \u003c\/svg\u003e\n      \u003c\/span\u003e\n      \u003cspan\u003eDownload Excel\u003c\/span\u003e\n    \u003c\/button\u003e\n    \u003cbutton class=\"sic-button sic-button-secondary sic-reset\" type=\"button\"\u003eReset\u003c\/button\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"sic-workspace\"\u003e\n    \u003csection class=\"sic-panel sic-input-panel\" aria-labelledby=\"sic-input-heading\"\u003e\n      \u003ch3 id=\"sic-input-heading\"\u003eInputs\u003c\/h3\u003e\n      \u003cp class=\"sic-panel-intro\"\u003eChoose the unknown variable. That field becomes the live calculated result while the other three remain editable.\u003c\/p\u003e\n\n      \u003cfieldset class=\"sic-solve-fieldset\"\u003e\n        \u003clegend\u003eSolve for\u003c\/legend\u003e\n        \u003cdiv class=\"sic-segments\"\u003e\n          \u003cinput class=\"sic-segment-input sic-mode\" id=\"sic-mode-balance\" name=\"sic-mode\" type=\"radio\" value=\"balance\" checked\u003e\n          \u003clabel class=\"sic-segment-label\" for=\"sic-mode-balance\"\u003eEnd balance\u003c\/label\u003e\n          \u003cinput class=\"sic-segment-input sic-mode\" id=\"sic-mode-principal\" name=\"sic-mode\" type=\"radio\" value=\"principal\"\u003e\n          \u003clabel class=\"sic-segment-label\" for=\"sic-mode-principal\"\u003ePrincipal\u003c\/label\u003e\n          \u003cinput class=\"sic-segment-input sic-mode\" id=\"sic-mode-term\" name=\"sic-mode\" type=\"radio\" value=\"term\"\u003e\n          \u003clabel class=\"sic-segment-label\" for=\"sic-mode-term\"\u003eTerm\u003c\/label\u003e\n          \u003cinput class=\"sic-segment-input sic-mode\" id=\"sic-mode-rate\" name=\"sic-mode\" type=\"radio\" value=\"rate\"\u003e\n          \u003clabel class=\"sic-segment-label\" for=\"sic-mode-rate\"\u003eRate\u003c\/label\u003e\n        \u003c\/div\u003e\n      \u003c\/fieldset\u003e\n\n      \u003cdiv class=\"sic-fields\"\u003e\n        \u003cdiv class=\"sic-field\"\u003e\n          \u003clabel class=\"sic-label\" for=\"sic-principal\"\u003ePrincipal amount\u003c\/label\u003e\n          \u003cinput class=\"sic-input sic-money\" id=\"sic-principal\" inputmode=\"decimal\" type=\"text\" value=\"$20,000.00\" aria-describedby=\"sic-principal-help sic-principal-error\"\u003e\n          \u003cdiv class=\"sic-helper\" id=\"sic-principal-help\"\u003eThe original amount borrowed, lent, or invested.\u003c\/div\u003e\n          \u003cdiv class=\"sic-error\" id=\"sic-principal-error\"\u003e\u003c\/div\u003e\n        \u003c\/div\u003e\n\n        \u003cdiv class=\"sic-field\"\u003e\n          \u003clabel class=\"sic-label\" for=\"sic-balance\"\u003eEnd balance\u003c\/label\u003e\n          \u003cinput class=\"sic-input sic-money\" id=\"sic-balance\" inputmode=\"decimal\" type=\"text\" value=\"$26,000.00\" readonly aria-describedby=\"sic-balance-help sic-balance-error\"\u003e\n          \u003cdiv class=\"sic-helper\" id=\"sic-balance-help\"\u003ePrincipal plus all simple interest over the term.\u003c\/div\u003e\n          \u003cdiv class=\"sic-error\" id=\"sic-balance-error\"\u003e\u003c\/div\u003e\n        \u003c\/div\u003e\n\n        \u003cdiv class=\"sic-field\"\u003e\n          \u003clabel class=\"sic-label\" for=\"sic-rate\"\u003eInterest rate\u003c\/label\u003e\n          \u003cdiv class=\"sic-control-row\"\u003e\n            \u003cinput class=\"sic-input sic-percent\" id=\"sic-rate\" inputmode=\"decimal\" type=\"text\" value=\"3.00%\" aria-describedby=\"sic-rate-help sic-rate-error\"\u003e\n            \u003cdiv class=\"sic-field\"\u003e\n              \u003clabel class=\"sic-label\" for=\"sic-rate-unit\"\u003eRate basis\u003c\/label\u003e\n              \u003cselect class=\"sic-select\" id=\"sic-rate-unit\"\u003e\n                \u003coption value=\"year\" selected\u003eper year\u003c\/option\u003e\n                \u003coption value=\"month\"\u003eper month\u003c\/option\u003e\n              \u003c\/select\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n          \u003cdiv class=\"sic-helper\" id=\"sic-rate-help\"\u003eEnter the simple rate for the selected period.\u003c\/div\u003e\n          \u003cdiv class=\"sic-error\" id=\"sic-rate-error\"\u003e\u003c\/div\u003e\n        \u003c\/div\u003e\n\n        \u003cdiv class=\"sic-field\"\u003e\n          \u003clabel class=\"sic-label\" for=\"sic-term\"\u003eTerm\u003c\/label\u003e\n          \u003cdiv class=\"sic-control-row\"\u003e\n            \u003cinput class=\"sic-input sic-number\" id=\"sic-term\" inputmode=\"decimal\" type=\"text\" value=\"10\" aria-describedby=\"sic-term-help sic-term-error\"\u003e\n            \u003cdiv class=\"sic-field\"\u003e\n              \u003clabel class=\"sic-label\" for=\"sic-term-unit\"\u003eTerm unit\u003c\/label\u003e\n              \u003cselect class=\"sic-select\" id=\"sic-term-unit\"\u003e\n                \u003coption value=\"years\" selected\u003eyears\u003c\/option\u003e\n                \u003coption value=\"months\"\u003emonths\u003c\/option\u003e\n              \u003c\/select\u003e\n            \u003c\/div\u003e\n          \u003c\/div\u003e\n          \u003cdiv class=\"sic-helper\" id=\"sic-term-help\"\u003eThe full duration; partial years and months are supported.\u003c\/div\u003e\n          \u003cdiv class=\"sic-error\" id=\"sic-term-error\"\u003e\u003c\/div\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n\n      \u003cdiv class=\"sic-form-note\"\u003eSimple interest is calculated only on the original principal. It does not add prior interest back into the interest-bearing base.\u003c\/div\u003e\n    \u003c\/section\u003e\n\n    \u003csection class=\"sic-panel sic-results\" aria-labelledby=\"sic-results-heading\"\u003e\n      \u003ch3 id=\"sic-results-heading\"\u003eLive results\u003c\/h3\u003e\n      \u003cdiv class=\"sic-primary-result\" aria-live=\"polite\" aria-atomic=\"true\"\u003e\n        \u003cdiv class=\"sic-result-eyebrow sic-primary-label\"\u003eEnd balance\u003c\/div\u003e\n        \u003cdiv class=\"sic-result-value sic-primary-value\"\u003e$26,000.00\u003c\/div\u003e\n        \u003cdiv class=\"sic-result-summary sic-primary-summary\"\u003e$20,000.00 principal plus $6,000.00 simple interest.\u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"sic-result-grid\"\u003e\n        \u003cdiv class=\"sic-metric\"\u003e\n          \u003cdiv class=\"sic-metric-label\"\u003eTotal interest\u003c\/div\u003e\n          \u003cdiv class=\"sic-metric-value sic-total-interest\"\u003e$6,000.00\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-metric\"\u003e\n          \u003cdiv class=\"sic-metric-label\"\u003eInterest per year\u003c\/div\u003e\n          \u003cdiv class=\"sic-metric-value sic-interest-year\"\u003e$600.00\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-metric\"\u003e\n          \u003cdiv class=\"sic-metric-label\"\u003eInterest per month\u003c\/div\u003e\n          \u003cdiv class=\"sic-metric-value sic-interest-month\"\u003e$50.00\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-metric\"\u003e\n          \u003cdiv class=\"sic-metric-label\"\u003eInterest share of final balance\u003c\/div\u003e\n          \u003cdiv class=\"sic-metric-value sic-interest-share\"\u003e23.08%\u003c\/div\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"sic-formula\"\u003e\n\u003cstrong\u003eCurrent formula:\u003c\/strong\u003e \u003cspan class=\"sic-formula-text\"\u003eA = P × (1 + r × t)\u003c\/span\u003e\n\u003c\/div\u003e\n    \u003c\/section\u003e\n  \u003c\/div\u003e\n\n  \u003csection class=\"sic-section sic-breakdown\" aria-labelledby=\"sic-breakdown-heading\"\u003e\n    \u003cdiv class=\"sic-section-heading\"\u003e\n      \u003ch3 id=\"sic-breakdown-heading\"\u003eBalance breakdown\u003c\/h3\u003e\n      \u003cp class=\"sic-section-copy\"\u003ePrincipal and total simple interest as shares of the ending balance.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"sic-breakdown-grid\"\u003e\n      \u003carticle class=\"sic-card sic-chart-card sic-breakdown-card\" data-sic-chart-card=\"breakdown\"\u003e\n        \u003cdiv class=\"sic-chart-title-row\"\u003e\n          \u003cdiv class=\"sic-chart-total sic-breakdown-total\"\u003e$26,000.00 total\u003c\/div\u003e\n          \u003cdiv class=\"sic-chart-interpretation sic-breakdown-interpretation\"\u003eInterest contributes 23.08% of the final balance.\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-chart-cluster\"\u003e\n          \u003cdiv class=\"sic-plot sic-donut-plot\" data-sic-plot\u003e\u003c\/div\u003e\n          \u003cdiv class=\"sic-legend sic-breakdown-legend\" data-sic-legend\u003e\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-chart-empty sic-breakdown-empty\"\u003eEnter values above to see the breakdown.\u003c\/div\u003e\n        \u003cdiv class=\"sic-data-summary\"\u003e\n          \u003cdiv class=\"sic-table-wrap\"\u003e\n            \u003ctable class=\"sic-table sic-breakdown-table\"\u003e\n              \u003cthead\u003e\n                \u003ctr\u003e\n\u003cth\u003eComponent\u003c\/th\u003e\n\u003cth class=\"sic-num\"\u003eAmount\u003c\/th\u003e\n\u003cth class=\"sic-num\"\u003eShare\u003c\/th\u003e\n\u003c\/tr\u003e\n              \u003c\/thead\u003e\n              \u003ctbody class=\"sic-breakdown-body\"\u003e\u003c\/tbody\u003e\n            \u003c\/table\u003e\n          \u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-chart-callout sic-breakdown-callout\"\u003eThe interest segment grows linearly because the same amount of interest is added for each equal period.\u003c\/div\u003e\n      \u003c\/article\u003e\n\n      \u003carticle class=\"sic-card sic-chart-card sic-line-card\" data-sic-chart-card=\"line\"\u003e\n        \u003cdiv class=\"sic-chart-title-row\"\u003e\n          \u003cdiv class=\"sic-chart-total\"\u003eBalance accumulation\u003c\/div\u003e\n          \u003cdiv class=\"sic-chart-interpretation sic-line-interpretation\"\u003eThe balance increases by $600.00 per year.\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-chart-cluster\"\u003e\n          \u003cdiv class=\"sic-plot sic-line-plot\" data-sic-plot\u003e\u003c\/div\u003e\n          \u003cdiv class=\"sic-legend sic-line-legend\" data-sic-legend\u003e\u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-chart-empty sic-line-empty\"\u003eEnter a positive principal and term to see the accumulation chart.\u003c\/div\u003e\n        \u003cdiv class=\"sic-data-summary\"\u003e\n          \u003cdiv class=\"sic-table-wrap\"\u003e\n            \u003ctable class=\"sic-table sic-chart-summary-table\"\u003e\n              \u003cthead\u003e\n                \u003ctr\u003e\n\u003cth\u003eCheckpoint\u003c\/th\u003e\n\u003cth class=\"sic-num\"\u003ePrincipal\u003c\/th\u003e\n\u003cth class=\"sic-num\"\u003eInterest\u003c\/th\u003e\n\u003cth class=\"sic-num\"\u003eBalance\u003c\/th\u003e\n\u003c\/tr\u003e\n              \u003c\/thead\u003e\n              \u003ctbody class=\"sic-chart-summary-body\"\u003e\u003c\/tbody\u003e\n            \u003c\/table\u003e\n          \u003c\/div\u003e\n        \u003c\/div\u003e\n        \u003cdiv class=\"sic-chart-callout sic-line-callout\"\u003eThe straight accumulation line is the defining visual pattern of simple interest: equal time intervals add equal interest amounts.\u003c\/div\u003e\n      \u003c\/article\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"sic-section sic-table-section\" aria-labelledby=\"sic-schedule-heading\"\u003e\n    \u003cdiv class=\"sic-section-heading\"\u003e\n      \u003cdiv\u003e\n        \u003ch3 id=\"sic-schedule-heading\"\u003eInterest schedule\u003c\/h3\u003e\n        \u003cp class=\"sic-section-copy\"\u003eEach row uses the same principal and rate; only elapsed time changes.\u003c\/p\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"sic-table-controls\"\u003e\n        \u003cdiv class=\"sic-table-control\"\u003e\n          \u003clabel class=\"sic-label\" for=\"sic-schedule-view\"\u003eSchedule detail\u003c\/label\u003e\n          \u003cselect class=\"sic-select\" id=\"sic-schedule-view\"\u003e\n            \u003coption value=\"annual\" selected\u003eAnnual\u003c\/option\u003e\n            \u003coption value=\"monthly\"\u003eMonthly\u003c\/option\u003e\n          \u003c\/select\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"sic-card sic-schedule-card\"\u003e\n      \u003cdiv class=\"sic-table-wrap sic-schedule-wrap\"\u003e\n        \u003ctable class=\"sic-table sic-schedule-table\"\u003e\n          \u003cthead\u003e\n            \u003ctr\u003e\n              \u003cth\u003ePeriod\u003c\/th\u003e\n              \u003cth class=\"sic-num\"\u003eElapsed time\u003c\/th\u003e\n              \u003cth class=\"sic-num\"\u003eInterest this period\u003c\/th\u003e\n              \u003cth class=\"sic-num\"\u003eCumulative interest\u003c\/th\u003e\n              \u003cth class=\"sic-num\"\u003eBalance\u003c\/th\u003e\n            \u003c\/tr\u003e\n          \u003c\/thead\u003e\n          \u003ctbody class=\"sic-schedule-body\"\u003e\u003c\/tbody\u003e\n        \u003c\/table\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"sic-table-note sic-schedule-note\"\u003eThe final row always lands on the exact entered term, including partial years or months. Monthly detail is limited to terms of 100 years or less.\u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\n  \u003csection class=\"sic-education\" aria-labelledby=\"sic-education-heading\"\u003e\n    \u003cdiv class=\"sic-education-grid\"\u003e\n      \u003carticle class=\"sic-education-section\"\u003e\n        \u003ch2 id=\"sic-education-heading\"\u003eHow to use and interpret this simple interest calculator\u003c\/h2\u003e\n        \u003cp\u003eThis calculator estimates a final balance, starting principal, term, or simple interest rate from the other three values. It is designed for arrangements where interest is based on the original principal throughout the full term. That assumption is materially different from compounding, amortization, or a daily-balance loan whose principal changes after payments.\u003c\/p\u003e\n\n        \u003ch3\u003eChoose the variable you need to solve\u003c\/h3\u003e\n        \u003cp\u003eThe \u003cstrong\u003eSolve for\u003c\/strong\u003e control determines which field is calculated. Select \u003cstrong\u003eEnd balance\u003c\/strong\u003e to project principal plus interest. Select \u003cstrong\u003ePrincipal\u003c\/strong\u003e when you know a target balance, rate, and term and need the required starting amount. Select \u003cstrong\u003eTerm\u003c\/strong\u003e to estimate how long it takes to move from principal to a target balance at a fixed simple rate. Select \u003cstrong\u003eRate\u003c\/strong\u003e to find the simple rate implied by a known principal, ending balance, and duration. The calculated field is highlighted and read-only, so there is no ambiguity about which value is the output.\u003c\/p\u003e\n\n        \u003ch3\u003eField-by-field guidance\u003c\/h3\u003e\n        \u003cul\u003e\n          \u003cli\u003e\n\u003cstrong\u003ePrincipal amount:\u003c\/strong\u003e Enter the original amount borrowed, lent, or invested. It is required unless principal is the selected unknown. A higher principal increases total interest proportionally when rate and time remain unchanged. Do not include interest, origination fees, taxes, or later deposits unless the agreement explicitly treats them as part of the principal.\u003c\/li\u003e\n          \u003cli\u003e\n\u003cstrong\u003eEnd balance:\u003c\/strong\u003e Enter principal plus all simple interest due at the end of the term. It is required when solving for principal, term, or rate. An end balance below principal would imply a negative return, which this calculator intentionally rejects because it is outside the standard nonnegative simple-interest model.\u003c\/li\u003e\n          \u003cli\u003e\n\u003cstrong\u003eInterest rate:\u003c\/strong\u003e Enter the rate for the selected basis. Choose \u003cstrong\u003eper year\u003c\/strong\u003e for an annual rate or \u003cstrong\u003eper month\u003c\/strong\u003e for a monthly rate. Switching the basis converts the current value so the economic result stays unchanged. For example, 12% per year becomes 1% per month under the proportional simple-rate convention. The rate is required unless rate is the selected unknown.\u003c\/li\u003e\n          \u003cli\u003e\n\u003cstrong\u003eTerm:\u003c\/strong\u003e Enter the duration in years or months. Switching units converts the current value rather than relabeling it. Ten years becomes 120 months, and 18 months becomes 1.5 years. The term must be positive whenever it is used to solve another variable.\u003c\/li\u003e\n          \u003cli\u003e\n\u003cstrong\u003eSchedule detail:\u003c\/strong\u003e Annual rows are concise and align with common annual rates. Monthly rows are useful for short-term contracts or monthly rates. Changing this view does not change the calculation; it only changes how the same model is displayed and exported.\u003c\/li\u003e\n        \u003c\/ul\u003e\n\n        \u003ch3\u003eThe formula in practical terms\u003c\/h3\u003e\n        \u003cdiv class=\"sic-equation\"\u003eInterest = Principal × Rate × Time\u003c\/div\u003e\n        \u003cp\u003eThe rate and time must use compatible periods. This calculator normalizes both to annual units internally, then computes total interest. The ending balance equals principal plus total interest. Solving for another variable is algebraic rearrangement: principal equals ending balance divided by one plus rate-times-time; term equals the balance growth factor divided by the rate; and rate equals the balance growth factor divided by time.\u003c\/p\u003e\n        \u003cp\u003eBecause prior interest never joins the interest-bearing base, the balance grows in a straight line. Every equal period adds the same dollar amount. For the default example, $20,000 at 3% per year produces $600 each year, $6,000 over ten years, and a $26,000 end balance.\u003c\/p\u003e\n\n        \u003ch3\u003eUnderstanding every result\u003c\/h3\u003e\n        \u003cp\u003eThe \u003cstrong\u003eprimary result\u003c\/strong\u003e is whichever variable you selected. \u003cstrong\u003eTotal interest\u003c\/strong\u003e measures the dollar difference between end balance and principal. A zero value means the rate or time is zero. \u003cstrong\u003eInterest per year\u003c\/strong\u003e is principal multiplied by the annual simple rate; \u003cstrong\u003einterest per month\u003c\/strong\u003e is one-twelfth of that amount. \u003cstrong\u003eInterest share of final balance\u003c\/strong\u003e shows how much of the ending total comes from interest rather than original capital.\u003c\/p\u003e\n        \u003cp\u003eThe donut chart uses the same principal and interest values as the breakdown table. A larger interest share can be caused by a higher rate, a longer term, or both. The accumulation chart plots principal, cumulative interest, and total balance over time. Its straight slope is not a forecast of market returns; it is a visualization of the fixed simple-interest assumption. The schedule shows interest added during each row, cumulative interest to date, and the resulting balance. Its last row should match the displayed final balance exactly.\u003c\/p\u003e\n\n        \u003ch3\u003eSimple interest versus other lending methods\u003c\/h3\u003e\n        \u003cp\u003eReal contracts may use simple interest, precomputed interest, amortization, daily balances, fees, or compounding. The Consumer Financial Protection Bureau explains the distinction between \u003ca href=\"https:\/\/www.consumerfinance.gov\/ask-cfpb\/whats-the-difference-between-a-simple-interest-rate-and-precomputed-interest-on-an-auto-loan-en-841\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003esimple and precomputed interest\u003c\/a\u003e, while its guide to \u003ca href=\"https:\/\/www.consumerfinance.gov\/ask-cfpb\/what-is-the-difference-between-a-loan-interest-rate-and-the-apr-en-733\/\" target=\"_blank\" rel=\"noopener noreferrer\"\u003einterest rate versus APR\u003c\/a\u003e shows why fees can make APR higher than the stated rate. For investments that reinvest earnings, compare the result with the SEC’s \u003ca href=\"https:\/\/www.investor.gov\/financial-tools-calculators\/calculators\/compound-interest-calculator\" target=\"_blank\" rel=\"noopener noreferrer\"\u003ecompound interest calculator\u003c\/a\u003e.\u003c\/p\u003e\n\n        \u003ch3\u003eCommon mistakes and decision limits\u003c\/h3\u003e\n        \u003cul\u003e\n          \u003cli\u003eDo not enter 5 for a monthly rate when the quoted figure is 5% annually. Match the rate basis to the contract.\u003c\/li\u003e\n          \u003cli\u003eDo not treat APR as the simple rate when APR includes fees or other charges.\u003c\/li\u003e\n          \u003cli\u003eDo not use this model for a declining-balance loan unless the lender explicitly computes interest on the original principal for the entire term.\u003c\/li\u003e\n          \u003cli\u003eDo not assume interest earned is automatically tax-free. In the United States, the IRS notes that many forms of \u003ca href=\"https:\/\/www.irs.gov\/taxtopics\/tc403\" target=\"_blank\" rel=\"noopener noreferrer\"\u003einterest received may be taxable\u003c\/a\u003e; rules vary by jurisdiction and account type.\u003c\/li\u003e\n          \u003cli\u003eUse the E\nxcel export to document assumptions, but verify the actual contract’s day-count convention, payment timing, fees, penalties, and rounding rules before making a financial decision.\u003c\/li\u003e\n        \u003c\/ul\u003e\n        \u003cp\u003eThis tool provides general educational estimates, not personalized financial, tax, legal, or investment advice.\u003c\/p\u003e\n      \u003c\/article\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\u003c\/div\u003e","brand":"FinancialModelsLab","offers":[{"title":"Default Title","offer_id":49909484421363,"sku":"simple-interest-calculator","price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0522\/6191\/2762\/files\/simple-interest-calculator.webp?v=1783935444","url":"https:\/\/financialmodelslab.com\/products\/simple-interest-calculator","provider":"Financial Models Lab","version":"1.0","type":"link"}