Convert Fahrenheit to Celsius

About converting Fahrenheit to Celsius

Fahrenheit (°F) and Celsius (°C) are different temperature scales, so they convert with a formula rather than a simple ratio: °C = (°F − 32) × 5/9. That is why 100 Fahrenheit is 37.7778 Celsius but 1 Fahrenheit is -17.2222 Celsius — the scales have different zero points, so you cannot just multiply.

What is a Fahrenheit?

Daniel Gabriel Fahrenheit published his scale in 1724, building it around fixed points he could actually reproduce in a workshop: zero was set by a freezing brine of ice, water and salt — about the coldest he could reliably make — and the upper anchor sat near human body temperature. Officially it survives today essentially only in the United States and a handful of territories. Its one genuine advantage is granularity: its degrees are smaller, so ordinary weather spreads across a wider span of whole numbers, and 0 to 100 maps roughly onto the range of human comfort.

What is a Celsius?

Anders Celsius proposed his scale in 1742 with the numbers running backwards: 0 marked the boiling point of water and 100 its freezing point. It was inverted to the familiar arrangement shortly after his death. The unit was called centigrade until 1948, when the international body governing measurement settled on Celsius instead, partly because "grade" already meant a different thing in French. The scale is no longer defined by water at all — it is derived from the kelvin, offset by 273.15, with the curious result that water’s boiling point now falls a fraction below a tidy 100.

To put both in perspective: water freezes at 32 degrees Fahrenheit, while water freezes at 0 degrees Celsius.

The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Celsius to Fahrenheit converter, or browse all Temperature converters.