Unit Converter

How it works

Choose a category, enter a value, then pick the units to convert from and to. Only units in the chosen category are offered, so a length can never be converted to a mass. This page shares its unit definitions and exact factors with Numerila’s specialist converters, so a result here always matches theirs. When you pick a category, a link to its specialist converter appears for more units and the notes that go with them.

Each category keeps its own rules. Mass, area, volume, speed, data storage, density, frequency and fuel economy do not accept negative values; temperature accepts them down to absolute zero; energy, power, pressure and angle accept signed values. Temperature here covers °C, °F and K only (Gas Mark is in the Temperature Converter), and volume lists general units only.

A result written as a plain number is exact. A result starting with “≈” has been rounded to 10 significant figures, because its exact decimal never ends or is too long to read comfortably. When an exact value is long, its full digits are shown underneath. The calculation itself is never rounded: only the display is.