Profit & margin calculator for online sellers

Enter a price and your costs to see what you keep after fees, shipping and ad spend, plus the lowest price that still breaks even.

How it's calculated

All math runs in your browser. Revenue is what the buyer pays you for the order: the item price plus any shipping you charge, before sales tax.

Metric	Formula
Fees	revenue × fee % + fixed fee per order
Net profit per order	revenue − COGS − your shipping cost − fees − ad spend per order
Net margin	net profit ÷ revenue
Gross margin	(price − COGS) ÷ price
Markup	(price − COGS) ÷ COGS
Break-even price	(fixed fee + COGS + shipping cost + ad spend) ÷ (1 − fee %) − shipping charged
Break-even sales / month	monthly fixed costs ÷ net profit per order, rounded up
Max ad spend per order	net profit + current ad spend (the CAC at which profit hits $0)
Break-even ROAS	revenue ÷ max ad spend per order

The eBay preset applies the $0.30 per-order fee on orders of $10 or less and $0.40 above $10, and uses 13.6% of the total sale, which covers most categories up to $7,500. Some categories, such as trading cards, sneakers and heavy equipment, use different rates.

What counts as product cost?

For thrifted or sourced inventory, COGS is what you paid for the item plus any cleaning or repair spend directly tied to it. Put recurring spend like store subscriptions, software and storage in monthly fixed costs. That way the break-even figure tells you how many sales a month keep the lights on.

Gross margin vs markup

A $40 item that cost $10 has a 75% gross margin but a 300% markup. Margin divides by price and can never exceed 100%; markup divides by cost. Sellers who mix the two up tend to underprice. For a deeper look at fees on eBay specifically, see our complete guide to selling on eBay, and when you're ready to run a sale, try the discount optimizer.

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