単位変換

A unit converter that handles the conversions you reach for every day across several categories: length, weight, temperature, volume, area, speed and digital storage, each with both metric and imperial units.

Pick a category, enter a value, choose the units to convert from and to, and the result appears instantly. A swap button flips the direction, which is handy when you realize you had the source and target the wrong way round.

Everything runs in your browser, instantly and offline once the page has loaded, with nothing sent to a server.

Conversions use precise, internationally defined factors rather than rough approximations. One inch is exactly 0.0254 metres, for instance, and results are shown to several significant figures so they are accurate enough for practical and technical work alike.

Temperature is the special case. Celsius, Fahrenheit and Kelvin do not just differ by a scale factor, they have different zero points, so the tool applies the correct offset formula rather than a simple multiplication.

Typical uses include converting a recipe from cups to millilitres, a height from feet and inches to centimetres, a speed limit from miles per hour to kilometres per hour, or a file size between units, without hunting for the right multiplier each time.