Loan Repayment Calculator | Loan Payoff Calculator
Loan Repayment Calculator
Estimate payments, total interest, payoff timing, a full amortization schedule, and the effect of extra monthly principal.
Loan specifications
Choose a level payment, constant principal, or an earlier balloon payoff.
Original principal before interest and fees.
Nominal annual rate; 0% is supported.
Enter the contractual amortization length.
The annual rate is converted to an equivalent monthly rate.
Applied directly to principal after scheduled interest.
The remaining balance is due at this point.
Advanced schedule options
Optional; used for schedule labels and Excel export.
Cash rounding may create a small final-payment adjustment.
Live results
Monthly payment
$118.70
Level scheduled payment before optional extra principal.
Repayment breakdown
See how principal and financing cost contribute to total cash paid.
Interest is calculated from the unpaid balance, so faster principal reduction generally lowers borrowing cost.
Balance and cumulative repayment
The chart tracks the remaining balance, principal repaid, and interest paid over time.
At the end of the schedule, cumulative principal should equal the original loan amount and the balance should be zero.
Amortization schedule
| Period | Payment | Principal | Interest | Extra / balloon | Ending balance |
|---|
Annual rows sum the underlying monthly schedule. Switch to monthly detail for every payment.
How to use the loan repayment calculator
This calculator estimates the cash flows of a fixed-rate installment loan. It can model three common structures: a level total payment, an even-principal schedule, and a balloon loan. The results are planning estimates rather than a lender quote. Actual statements may differ because of daily interest, fees, payment timing, escrow, promotional rates, or a lender’s rounding policy.
What each input means
Payment type controls how principal is returned. Even total payments keep the scheduled installment level while the interest share falls and the principal share rises. Even principal payments return the same scheduled principal each month, so the first payment is highest and later payments decline. A balloon structure calculates regular payments over the full amortization term but requires the remaining balance at the selected balloon date.
Loan amount is the opening principal. Enter the amount actually financed, not the sum of future payments. A higher principal increases the payment, total interest, and ending balloon balance in roughly direct proportion. Upfront charges should only be included when they are financed into the loan.
Annual interest rate is the nominal stated rate. Enter 7.5 for 7.5%, not 0.075. A higher rate raises the interest component and usually increases the scheduled payment. The calculator supports a zero rate, which divides principal evenly across the term. For consumer borrowing, compare the stated rate with the annual percentage rate and disclosures supplied by the lender. The Consumer Financial Protection Bureau explains the difference between interest rate and APR.
Loan term is the amortization horizon. A longer term usually lowers the required installment but keeps principal outstanding longer, increasing total interest. Switching between years and months converts the current value rather than merely changing the label. Fractions of a year are converted to whole monthly payment periods.
Compound frequency determines how the nominal annual rate becomes an equivalent monthly rate. Monthly compounding uses the annual rate divided by 12. For yearly, semiannual, or quarterly compounding, the calculator converts the stated periodic rate into an equivalent monthly rate. Confirm this convention against the note or agreement because lenders can use different accrual methods.
Extra monthly payment is additional principal paid with each regular installment. It is optional and must be nonnegative. On a normal amortizing loan, extra principal can shorten the payoff period and reduce interest. On a balloon loan, it generally reduces the balloon amount while the contractual balloon date remains unchanged. Verify that the loan has no prepayment restriction and that extra funds are applied to principal. The CFPB provides general guidance on paying a loan early.
Balloon payment after appears only for balloon loans. It must be positive and no later than the amortization term. A shorter balloon interval produces a larger final lump sum because less principal has been repaid through regular installments.
First payment month is optional. It gives calendar labels to monthly schedule rows and is exported to Excel. Schedule rounding keeps full mathematical precision by default and rounds only the displayed values. Cash rounding instead rounds each payment, interest amount, and principal amount to cents, which may slightly adjust the final payment.
How to read the results
The primary result is the scheduled payment for an even-total or balloon loan and the first payment for an even-principal loan. When extra principal is entered, the note distinguishes the required scheduled amount from the planned cash payment. Total repayment is the sum of all scheduled, extra, and balloon cash flows. Total interest is total repayment minus principal; it does not include separately charged fees.
Payoff duration counts the generated monthly payments. Time saved compares that duration with the same loan at zero extra payment. Interest saved makes the same comparison for total interest. A zero value means the extra payment does not change that measure, as can happen when there is no extra payment or when a balloon date fixes the schedule length. Final payment shows the last cash flow, which can be smaller than a regular payment after accelerated payoff or much larger for a balloon loan.
The effective monthly rate is the rate applied to the unpaid balance in each row. Balloon principal is the outstanding principal included in the final balloon payment; it is zero for fully amortizing schedules.
Understanding the charts and schedule
The repayment breakdown compares original principal with total interest. The segments and legend use the exact same model values, so their percentages sum to 100% of total repayment. A larger interest share indicates that financing cost is a greater portion of total cash paid.
The line chart shows remaining balance, cumulative principal repaid, and cumulative interest. The balance should trend toward zero. Cumulative principal should end at the original loan amount. Cumulative interest rises fastest when the balance is high, which is why extra principal usually has more impact when paid earlier.
The annual table aggregates monthly rows; the monthly view shows each calculation. Payment equals principal plus interest. The extra or balloon column isolates principal paid beyond the normal scheduled principal. Ending balance cannot fall below zero. The final row should show a zero balance, except that invalid or incomplete inputs intentionally produce no schedule.
Formula, tradeoffs, and common mistakes
For a level-payment loan, the calculator uses the standard annuity formula: payment equals principal multiplied by the monthly rate and the growth factor, divided by the growth factor minus one. At a zero rate, payment is principal divide d by the number of months. Each month’s interest equals the opening balance multiplied by the monthly rate; principal is the payment minus interest.
Lower payments are not automatically cheaper. Extending the term often lowers monthly pressure while raising lifetime interest. Extra payments can improve payoff speed but reduce liquidity, and a balloon loan can create refinancing risk if the lump sum is not available. Common mistakes include entering APR as the note rate, omitting financed fees from principal, assuming every lender compounds monthly, or treating an estimated schedule as a contract. For business borrowing, compare structures and eligibility through the U.S. Small Business Administration loan resources. Always reconcile the model with the lender’s official disclosure and payment instructions.