Fahrenheit to Celsius Converter

Fahrenheit to Celsius Converter

Fahrenheit is the everyday temperature scale in the United States, while Celsius is used across most of the world and in science. This free converter changes Fahrenheit (°F) into Celsius (°C) and back again, so you can read a US weather forecast, a recipe oven temperature, or a thermometer reading in the units you understand.

How it works

The converter applies the standard relation °C = (°F − 32) × 5/9, stored in the constant form °C = °F × 0.5555555556 − 17.77777778 (5/9 ≈ 0.5556 and 32 × 5/9 ≈ 17.778). The −32 offset accounts for the fact that the two scales place the freezing point of water differently: 32 °F versus 0 °C. Because of that offset the conversion is not a simple proportion — doubling the Fahrenheit value does not double the Celsius value. Type a value in either field and the opposite field updates instantly; the converter works in both directions.

Example

To convert 212 °F (the boiling point of water): °C = (212 − 32) × 5/9 = 180 × 5/9 = 100 °C. To convert body temperature 98.6 °F: (98.6 − 32) × 5/9 = 66.6 × 5/9 = 37 °C.

All calculations run entirely in your browser — no data is sent to any server.