CalcHub

CalcHub is a collection of free financial calculators that run entirely in your browser. The homepage lists tools for Stripe fees, TikTok creator rewards, YouTube revenue, SaaS MRR, and Shopify margins, all aimed at people who sell or publish online. I tried the Stripe fee calculator first and liked that numbers update as you type, with no page reload and no sign-up wall. Everything is calculated client-side, so your figures never leave the browser, and the site promises rate tables updated for 2026. There are seven interface languages if English is not your thing. The design is plain in a good way: no pop-ups, no upsell banners, just an input row and a result. If you regularly estimate payouts, margins, or MRR by hand, this saves the spreadsheet dance. Worth knowing: results are estimates, so check critical numbers against the payment processor itself before you commit to pricing.