Temperature Converter

Celsius, Fahrenheit, Kelvin.

Convert between Celsius, Fahrenheit and Kelvin instantly.

How it works

Fahrenheit is converted with °F = °C × 9/5 + 32, and Kelvin with K = °C + 273.15. Kelvin starts at absolute zero, so it never goes negative.

When it helps

Handy for travel weather, oven temperatures in foreign recipes, or science work.

The three scales

Celsius sets 0° at the freezing point of water and 100° at its boiling point at sea level. Fahrenheit puts those same points at 32° and 212°, so a Fahrenheit degree is smaller — 1.8 of them fit into one Celsius degree. Kelvin uses Celsius-sized steps but starts at absolute zero, −273.15 °C, the coldest possible temperature.

To go from Fahrenheit back to Celsius, subtract 32 and multiply by 5/9.

Worked examples

A US recipe baking at 350 °F needs (350 − 32) × 5/9 ≈ 177 °C, usually rounded to 180 °C. A 25 °C summer day is 77 °F. A 100.4 °F fever is 38 °C. Room temperature of 20 °C is 293.15 K.

A quick mental shortcut from Celsius to Fahrenheit is 'double it and add 30'. It's close for everyday weather but drifts at extreme temperatures, so use the exact result for cooking.

Frequently asked questions

At what temperature are Celsius and Fahrenheit equal?

At −40°. It's the same in both scales.

What is normal body temperature?

Around 37 °C, or 98.6 °F.

Why don't we say 'degrees Kelvin'?

Kelvin is an absolute scale, so the unit is simply 'kelvin' (K) without the degree sign.

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