Universal Temperature Converter

Convert across many related units. Enter your value and which unit it uses.

Alone among the universal converters, this one cannot reach its answer by multiplication. Three of its five scales place their zero somewhere different, so every entry is first resolved into Celsius and then rebuilt outward. Two of the five will be unfamiliar. Rankine is an absolute scale using Fahrenheit-sized degrees: its zero sits at absolute zero and water freezes at 491.67 °R, which keeps it in use across American thermodynamics and HVAC work where Fahrenheit intervals are already the habit. Réaumur puts zero at freezing and eighty at boiling, making each of its degrees exactly 1.25 Celsius degrees; it has all but disappeared, surviving mainly in traditional Italian and Swiss cheesemaking where curd temperatures are still spoken about in it. One degree Celsius accordingly emerges as 33.8 °F, 274.15 K, 493.47 °R and 0.8 °Ré, each rounded at six decimals and shown to four. Watch what Kelvin and Rankine do together: both take their zero from the same physical floor, so entering -273.15 °C sends the two of them negative at the same instant. Nothing on this page refuses a temperature below absolute zero, and no warning appears when you cross it. Delisle and Newton, the other historic scales, are not offered. Nor is any thermodynamic content — a temperature is not a quantity of heat, and reaching one from the other needs a mass and a specific heat capacity that this page never asks for.