About FeeMath

FeeMath makes free fee and profit calculators for people who sell online, covering 11 platforms. Each calculator uses the platform's current published US fees and runs in your browser.

We check fee rates regularly. The last full check was in October 2026. If you spot a rate that has changed, please let us know.

FeeMath is independent. We are not affiliated with or endorsed by any marketplace listed on this site. Some pages may contain ads or affiliate links, which help keep the tools free.