Temperature Converters

How hot or cold something is — Celsius, Fahrenheit and Kelvin.

Converters

Choose a converter

• Celsius to Fahrenheit °C → °F
• Fahrenheit to Celsius °F → °C
• Celsius to Kelvin °C → K
• Kelvin to Celsius K → °C

Background

What temperature units measure

Temperature is the odd one out. Every other unit on this site shares a zero — nothing weighs zero pounds and something else — so converting is one multiplication. The Celsius, Fahrenheit and Kelvin scales put their zero in three different places, so a conversion has to shift the number as well as scale it. That is why the formula has a "+ 32" in it and a weight formula never does.

Guide

Readings, differences and kelvin

A temperature reading and a temperature change convert differently. A thermostat set to 20 °C reads 68 °F, but warming a room by 20 °C warms it by 36 °F. The + 32 in the Fahrenheit formula belongs to readings only.

Kelvin is the scientific scale. It counts in steps the same size as Celsius but starts at absolute zero, −273.15 °C, so it never goes negative — and it is written without a degree sign: 300 K, not 300 °K.

Reference

Temperature units on this site

Every converter here calculates through degrees Celsius, so a pair and its reverse always agree. The full list of factors and the standards behind them is on the methodology page.