Converting units: length, mass, time, speed, energy, power, pressure, volume, temperature.
Mass, volume, pressure, energy and temperature — the conversions that come up when working with a substance.
Choose what is being measured and see the value in every unit of the group at once, not only in the one you asked for.
Factors are exact where the definition is exact: an inch is exactly 2.54 cm, a pound exactly 0.45359237 kg, a calorie exactly 4.184 J. Temperature converts with an offset as well as a factor, because kelvin and Celsius do not share a zero.
The arithmetic happens in your browser.