Unit Converter

One converter for everyday units

Length, weight, temperature, area, volume, speed, time and data - the everyday unit conversions, all in one place, converting instantly as you type. Pick a category, enter a value, choose your units, and read the exact result. It works fully offline in your browser, so it's there whether you're following a recipe, a workout, a DIY measurement or a physics problem.

Accurate, not approximate

The conversion factors follow international definitions, so results are exact rather than rounded rules of thumb: an inch is precisely 2.54 cm, a mile is 1,609.344 m, a pound is 0.453592 kg. Temperature is handled with the proper formulas (°F = °C × 1.8 + 32; Kelvin from absolute zero), not the linear scaling that works for other units. That precision matters when you're converting a medication dose, a machining measurement or an exam answer, where 'close enough' isn't.

When you need a dedicated tool

This handles the common categories in one place; for a few conversions a specialised tool does more. Currency needs live exchange rates - that's our Currency Converter. Time zones involve daylight saving and calendars - see the Time Zone Converter. Number bases (binary, hex, octal) and Roman numerals have their own dedicated converters too. For everything measured in physical units, though, this is the single tool to reach for.