Temperature Converter
Celsius, Fahrenheit, and Kelvin, converted both ways.
Common conversions
Temperature reference points
Familiar temperatures in all three scales.
| What | Celsius | Fahrenheit | Kelvin |
|---|
Why temperature conversion needs more than multiplying
Every other converter on this site works by multiplying by a fixed factor — 1 inch is always 2.54 cm, no matter what number you start with. Temperature doesn't work that way, because Celsius and Fahrenheit don't start counting from the same zero point.
Celsius sets 0° at water's freezing point. Fahrenheit sets 0° at a different, colder reference point entirely (originally based on a brine solution), so 0°C is actually 32°F, not 0°F. That offset has to be added or subtracted in addition to scaling for the different-sized degree steps — which is also why "twice as hot" isn't a meaningful idea in either scale: 20°C doubled is not the same temperature as 40°C measured on any other scale, since you'd be doubling a number that doesn't start at true zero.
Kelvin is the exception: it's the scale scientists use specifically because it starts at absolute zero — the coldest physically possible temperature, where 0 truly means "no thermal energy at all," which is why you'll never see a negative Kelvin value on this converter.