Skip to the calculator
Rule Calculator

Fahrenheit to Celsius

Subtract 32 first, then multiply by 5/9. Doing it in the other order is the single most common mistake in this conversion.

With temperature 72, temperature converter comes to 22.22 — converted value. It is reached in 4 steps, the last of which is celsius * to_c + fahrenheit * to_f + kelvin * to_k, and each one is printed on the page with its numbers filled in. The formula is the one published by NIST, not an approximation fitted to it.

Formula and sources checked · How we check

Converted value
22.22
In Celsius
value * from_c + (value - 32) * 5 / 9 * from_f + (value - 273.15) * from_k22.222 °C
In Fahrenheit
celsius * 9 / 5 + 3272 °F
In Kelvin
celsius + 273.15295.372 K
Converted value
celsius * to_c + fahrenheit * to_f + kelvin * to_k22.222

The formula

  1. In Celsiusvalue * from_c + (value - 32) * 5 / 9 * from_f + (value - 273.15) * from_k
  2. In Fahrenheitcelsius * 9 / 5 + 32
  3. In Kelvincelsius + 273.15
  4. Converted valuecelsius * to_c + fahrenheit * to_f + kelvin * to_k

Formula from NIST — SI units and temperature scales, BIPM — the kelvin and the International System of Units.

The same calculator, other cases

  • Celsius to FahrenheitMultiply by 9/5 and add 32. The offset is why this is not a factor like every other conversion on the site, and the page shows both parts.
  • Kelvin to CelsiusSubtract 273.15 — an exact figure, not a rounded one, because the two scales are defined to share a degree size.

Undecided? The Temperature Converter carries every case behind one control.

Did this answer your question?