Financial calculators

Financial calculators you can audit

Deterministic calculations, in your browser, with method and sources on display. No sign-up.

Free No sign-up

Tools

Start with a calculator

Each tool runs in your browser and shows its method. More to come.

Selling price from cost and markup.

Deadlines and due dates, holidays included.

Simple and compound interest per period.

Coming soon

Spreadsheet template

Markup spreadsheet: cost → price, markup vs. margin, multiple items.