About IFCalculator

A free, independent calculator library.

IFCalculator is a free collection of accurate calculators for finance, fitness, building, science, unit conversion, dates and everyday math. Every tool runs in your browser, works on any device, and needs no account.

What we believe

A calculator page should answer one question quickly and honestly. The working tool comes first, the formula behind it is shown, and we add only the reference material a result actually needs, no padding.

• The tool is the point: it computes correctly and updates as you type.
• Formulas are shown in full and sourced, so you can check the math yourself.
• No sign-up, no paywalls, and no manufactured ratings.

How it is built

Each calculator implements a named, published formula and is checked for correct output and clear wording before it goes live. We revise rates and formulas as standards change.