ToolwebHow to use this tool
- Enter cost and sale price using a consistent VAT basis.
- Set the fee percentage of sale price and additional costs per sale.
- Compare monetary profit, revenue margin, cost-based markup and break-even price.
Subtract costs from a KRW 15,000 sale
- Input and settings
- Cost KRW 10,000; sale price 15,000; fee 3%; other costs 1,000
- Result
- Fee KRW 450; profit KRW 3,550; revenue margin approximately 23.67%
The 35.5% purchase-cost-based markup is a different ratio from revenue margin.
Revenue margin and purchase-cost markup
Profit equals sale price minus purchase cost, the proportional selling fee and per-sale costs. Revenue margin divides by sale price, whereas purchase-cost markup divides by purchase cost; their percentages differ for the same transaction.
A zero purchase cost makes that markup undefined. Sale price must be positive; losses are retained as negative profit and negative ratios rather than hidden.
Assumptions behind break-even price
Break-even price divides purchase and other costs by one minus the fee fraction. At a 100% fee there is no finite break-even selling price, so none is fabricated.
Tiered fees or separately collected shipping charges change actual settlement. Do not mix VAT bases, and assess inventory losses, income taxes and fixed overhead separately.
Common questions
Is a 3% fee applied to purchase cost?
The fee percentage applies to the entire entered sale price. If a platform uses another settlement basis, compare its actual fee before applying this model.