About

Most sellers do not lose money on a single bad decision. They lose it on a hundred small miscalculations that all point the same way.

SkuMath exists because the arithmetic behind a product's profitability is spread across a dozen places — a marketplace rate card, a supplier quote, a freight invoice, an ad dashboard — and almost nobody assembles it into one number before committing to inventory.

Every calculator shows its formula

No black boxes. Each calculator lists the exact formula it uses, so you can check it, adjust the assumptions, or copy it into your own spreadsheet. If a number looks wrong, you should be able to see why within a few seconds.

What this site is not

• It is not accounting software. Nothing is stored, nothing is filed, no tax forms are produced.
• It is not financial or legal advice. These are planning estimates.
• It does not require an account. Every calculator runs in your browser.

Accuracy

Marketplace fee rates, storage rates and tax rules change. Defaults in these calculators are realistic starting points, not guarantees — check the current rate card for your category and region before making a purchasing decision. Fee-related calculators deliberately ask you to supply the rate where it varies by category, so the calculation stays correct even after rates change.

Privacy

Calculations run entirely in your browser. Your inputs are never sent anywhere. See the privacy page for the details.