What this converter does
This converter turns temperature between Fahrenheit, Celsius, Kelvin and Rankine — instantly and with the exact formulas, not rounded factors. Type a value, pick the scales, and the answer updates as you type. Temperature scales have an offset as well as a ratio, so both are handled.
To go Fahrenheit to Celsius, subtract 32 and multiply by 5/9. Kelvin uses the Celsius degree from absolute zero; Rankine uses the Fahrenheit degree from absolute zero. For weather, cooking and body temperature, the °F ↔ °C pair is the everyday one.
The units it covers
These scales share the same physical quantity but differ in both zero point and degree size.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Fahrenheit | °F | water 32–212 | US everyday temperature |
| Celsius | °C | water 0–100 | Everyday metric temperature |
| Kelvin | K | from 0 abs | SI, science, absolute zero |
| Rankine | °R | from 0 abs | US engineering, absolute °F |
The formula
Fahrenheit to Celsius shifts the zero point then scales the degree:
°C = (°F − 32) × 5⁄9 (and °F = (°C × 9⁄5) + 32)Where:
- °F = the Fahrenheit temperature
- °C = the Celsius temperature
- 5⁄9 = the degree-size ratio (0.5556)
Worked example
Convert 98.6 °F to Celsius.
98.6 − 32 = 66.666.6 × 5⁄9 = 37 °CSo 98.6 °F is 37 °C — normal human body temperature.
The units in this example
The US everyday scale, with water freezing at 32 and boiling at 212. A Fahrenheit degree is 5⁄9 of a Celsius degree.
- 32 °F = 0 °C
- 98.6 °F = 37 °C
- 212 °F = 100 °C
- −40 °F = −40 °C
The everyday metric temperature scale, with water freezing at 0 and boiling at 100 under standard pressure. It shares its degree size with Kelvin.
- 0 °C = 32 °F
- 37 °C = 98.6 °F
- 100 °C = 212 °F
- 0 °C = 273.15 K