Temperature converter

How to use

Temperature scales move in different steps and, unlike length, they do not share a starting point. Converting between Celsius, Fahrenheit and Kelvin therefore needs two corrections: the size of the degree and the offset, which is why 0 °C is 32 °F while 0 °F is not 0 °C.

• Follow a recipe written in Fahrenheit with a Celsius oven.
• Understand a weather report from another country.
• Convert a value for a science or engineering exercise.

1. Enter the temperature and choose the scale it is written in.
2. Choose the scale you want to read it in.
3. The result applies the factor and the offset of both scales, not only a multiplication.

Formula

°F = °C × 9/5 + 32 · °C = (°F − 32) × 5/9 · K = °C + 273.15

Example

20 °C is 68 °F and 293.15 K. At −40 the two scales meet: −40 °C equals −40 °F — the only point where that happens.

Limitations

• Kelvin is written without a degree sign, and its zero is absolute zero, not the freezing point of water.
• A value below absolute zero has no physical meaning even though the arithmetic still returns a number.

Frequently asked questions