Temperature Converter
Convert temperatures between Celsius, Fahrenheit and Kelvin.
How to use the Temperature Converter
- Type the reading into the Value box; the result updates as you type, with no button to press.
- Choose the scale you have in From and the one you want in To. The page opens on Celsius to Fahrenheit.
- Read the converted figure below, rounded to two decimal places.
The one reading where Celsius and Fahrenheit agree
Minus 40 is the same temperature on both scales, and it is the only one. Fahrenheit is Celsius times 9/5 plus 32, so the scales close on each other by 4/5 of a degree for every degree you descend, and the 32-degree offset runs out at minus 40.
Reference points on all three scales
Every row is exact rather than rounded. Kelvin is written as 300 K, never 300 degrees K, because it counts up from absolute zero rather than from a chosen reference point.
| Celsius | Fahrenheit | Kelvin |
|---|---|---|
| -273.15 | -459.67 | 0 |
| -40 | -40 | 233.15 |
| 0 | 32 | 273.15 |
| 20 | 68 | 293.15 |
| 37 | 98.6 | 310.15 |
| 100 | 212 | 373.15 |
Frequently asked questions
What is the Celsius to Fahrenheit formula?
Fahrenheit equals Celsius times 9/5 plus 32.
What is absolute zero?
Minus 273.15 degrees Celsius, or 0 Kelvin. It is the point where thermal motion reaches its minimum and no lower temperature is possible.
What is 100 degrees Fahrenheit in Celsius?
37.78 degrees Celsius. Subtract 32 and multiply by 5/9, which puts 100 F just above normal body temperature of 37 C, or 98.6 F.
Is there a way to convert Celsius in my head?
Double it and add 30. That runs between 2 degrees low and 4 degrees high over the 0 to 30 C range, close enough to decide what to wear.
Can I enter a temperature below absolute zero?
Nothing stops you, but the result is meaningless. A Celsius value under minus 273.15 returns a negative Kelvin figure, and no such temperature exists.