| Studio Rent |
Fixed |
Use $1,800 per month as fixed overhead from Month 1 through Month 60. |
Burying rent inside item margins instead of showing the sales needed to cover it. |
| Business Insurance |
Fixed |
Use $150 per month as fixed overhead in the monthly break-even base. |
Treating insurance as a per-order charge when it does not move with unit volume. |
| Website Hosting & Maintenance |
Fixed |
Use $50 per month as fixed overhead before calculating contribution margin. |
Netting it against online sales fees and losing visibility on true platform economics. |
| Utilities |
Semi-variable |
Start with the $350 monthly base, then monitor usage pressure as kiln, tool, and studio hours rise. |
Calling all utilities fixed even when production volume drives part of the bill. |
| Accounting Services |
Semi-fixed |
Use $250 per month until transaction volume or reporting needs force a step-up. |
Modeling it as a percentage of sales, which understates overhead at low volume. |
| Ceramic Mug - Raw Clay |
Variable |
Use $0.80 per mug as unit-level COGS, so it rises directly with mug production. |
Averaging materials across all products and hiding which items actually carry margin. |
| Ceramic Mug - Packaging |
Variable |
Use $0.50 per mug as a direct unit charge tied to each saleable item. |
Leaving packaging in overhead, which overstates contribution per mug. |
| E-commerce & Payment Fees |
Variable |
Use 4.0% of revenue in the first year, falling to 3.0% by the mature year. |
Ignoring selling fees when pricing products, especially on lower-priced dishes and mugs. |