About Numfino

Numfino is a free collection of financial calculators for loans, mortgages, saving, investing, budgeting and small-business math. The site is independent: it does not sell financial products, take referral fees from lenders or collect your data.

What we aim for

Every calculator should answer one question well, update as you type and show how it got there: the formula, a worked example, a chart and the full table. Articles explain how to read the result and what the calculator leaves out.

Calculators run entirely in your browser. The numbers you enter are not sent to a server or stored, apart from your currency choice, which your browser remembers on your device.

How content is made

Formulas are implemented once in a shared engine and tested against textbook results. Explanations are drafted with AI assistance, every worked example is generated by the same engine that powers the calculator, and sources are limited to regulators, government agencies and standard references. Pages show the date they were last reviewed.

If you find a mistake, email [email protected] and we will correct it.