Know what every order really earns you.

Why "6.5%" is never just 6.5%

Most sellers meet marketplace fees as a single headline number — Etsy charges 6.5%, Shopify advertises 2.9%. But the amount that actually leaves your order is a stack: a flat listing charge that punishes low-priced items, a percentage on the total including shipping, a payment processing fee with its own fixed component, and optional-but-not-really-optional advertising fees. On a $25 Etsy order to a US buyer, the effective fee rate is typically around 10%, not 6.5% — and on a $5 item it is far higher because the $0.20 listing fee and $0.25 processing fixed fee weigh proportionally more.

SellerMath exists to make that stack visible before you set a price, not after you get paid. Each tool is built around one decision: how to price an item, whether to offer free shipping, how much ad-attributed volume you can afford, or which Shopify plan fits your order volume. The math is shown on every page, with worked examples you can check yourself.

How these tools work

All calculators are plain HTML and JavaScript. There is no account, no tracking of your inputs, and no server-side calculation — when you type a price, the arithmetic happens in your browser tab. Fee rates come from official platform documentation and are reviewed periodically; the "last verified" date is shown on each page. Rates change, and your account may have specific terms, so treat results as planning estimates rather than payout statements.