What is actually left after eBay takes its cut — and what you would have to charge
to hit a margin you choose.
Net profit
—
How it is calculated
revenue = item price x qty + buyer-paid shipping (sales tax excluded - it is not yours)
eBay fees = final value fee + per-order fee + insertion fee
(fee is charged on the tax-inclusive total, even though the tax is not revenue)
ad cost = promoted listings rate x total amount of sale
net profit = revenue - eBay fees - cost of goods - your shipping cost - other - ad cost
margin = net profit / revenue
ROI = net profit / (cost of goods + your shipping cost)
Why sales tax appears on one side but not the other
eBay charges the final value fee on the total amount of the sale, and that total includes the sales
tax the buyer paid. The tax is remitted, so it never becomes your revenue. A calculator that drops the
tax from both sides understates your fees; one that keeps it on both sides overstates your margin.
This tool keeps it in the fee base and out of revenue.
Solving for a price
eBay's fee is a piecewise function — portion tiers, whole-amount cliffs, a per-order fee that steps
at $10, and a sneaker exemption at $150. There is no clean formula to invert it, so the target-margin
price is found by bisection over the same fee engine the calculator above uses, then rounded up to the
cent so the target is met rather than missed.