What this calculator tells you
Platform fees are variable costs that scale with revenue. A small percentage can become a major margin factor when order volume grows.
When to use it
Use it when comparing sales channels, setting a minimum price, or estimating the real revenue left after checkout.
Start with your landed cost, real fee rates, and a pessimistic advertising cost. The result is more useful when the assumptions are honest.
Multiplying only the commission rate by the selling price ignores fixed fees and payment processing charges.
Frequently asked questions
Should fees be calculated before or after tax?
Use the fee basis stated by your platform. Many platforms charge on the item or order total before some adjustments.
Why include a fixed fee?
Fixed fees have a larger effect on low-priced orders and should be included when comparing price points.
Does this include refunds?
Not directly. For a conservative view, increase the effective fee rate or subtract an expected refund cost.