Units · temperatureTemperature units

Convert temperature between Celsius, Fahrenheit, Kelvin and the historical scales. Type a value into any field — the rest update at once.

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01Convert02Reference points03About scales04Questions05Related
01

Temperature conversion

type a value into any scale — the others follow
Conversion · 2 decimals
Main scales
Kelvin and Rankine are absolute scales and take no degree sign: 300 K, not 300 °K.
Absolute
Historical
Precision
Common values
Result · from °C
Celsius20 °C
Fahrenheit68 °F
Kelvin293.15 K
Rankine527.67 °Ra
Réaumur16 °Ré
Newton6.6 °N
How it is calculated
C = введённое значение → F = C × 9/5 + 32, K = C + 273.15
Roughly thisroom temperature
02

Reference points

tap a row — the value goes into the converter
Point°C°FK°Ra
Absolute zero-273.15 °C-459.67 °F0 K0 °Ra
Water freezes0 °C32 °F273.15 K491.67 °Ra
Room temperature22 °C71.6 °F295.15 K531.27 °Ra
Human body36.6 °C97.88 °F309.75 K557.55 °Ra
Water boils (at sea level)100 °C212 °F373.15 K671.67 °Ra
Oven (medium)180 °C356 °F453.15 K815.67 °Ra
−40 is the only temperature where Celsius and Fahrenheit agree. 100 °C is boiling at sea level; higher up water boils cooler.

Oven temperature in Fahrenheit

how US oven dials round it
03

About temperature scales

Temperature is measured on several scales, and converting them is trickier than metres into kilometres: Celsius and Fahrenheit have different zero points, so a conversion is not only a factor but also a shift. Kelvin and Rankine count from absolute zero — the lowest temperature there is.

Celsius

Everyday & science
0 °C · 100 °C
Zero is tied to the freezing point of water and one hundred to its boiling point at sea level. The main scale in most countries and in everyday life.

Fahrenheit

USA
32 °F · 212 °F
Used in the United States. Water freezes at 32 °F and boils at 212 °F, with 180 degrees in between.

Kelvin

SI · absolute
0 K = −273.15 °C
The absolute SI scale: it counts from absolute zero and its step equals a degree Celsius. Written without a degree sign and never negative.

Why not just multiply

Offset
F = C × 9/5 + 32
Celsius and Fahrenheit have different zeros, so conversion is a scale plus a shift. Only Kelvin differs from Celsius by a shift alone (+273.15).

Absolute zero

Limit
−273.15 °C
The lowest possible temperature, where thermal motion of particles is minimal. Nothing is colder; this is where Kelvin and Rankine start.

Rankine, Réaumur and others

Historical
°Ra · °Ré
Rankine is “absolute Fahrenheit”, still seen in US engineering. Réaumur (0–80) turns up in old recipes and literature. Delisle and Newton are historical curiosities.
04

Frequently asked questions

Multiply by 9/5 and add 32: F = C × 9/5 + 32. For example, 20 °C = 68 °F, and 36.6 °C ≈ 97.9 °F.
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