Guide1 min readUpdated July 1, 2026
How to convert Celsius to Fahrenheit
Short answer
Multiply the Celsius value by 9/5 (1.8) and add 32. For example, 20 C x 1.8 + 32 = 68 F. To go the other way, subtract 32 and multiply by 5/9.
The formula
F = C x 9/5 + 32
C = (F - 32) x 5/9The scales differ in two ways: Fahrenheit degrees are smaller (there are 180 between freezing and boiling versus 100 in Celsius), and the zero points differ, which is why you both scale by 9/5 and shift by 32.
A quick mental shortcut
For a rough figure, double the Celsius value and add 30. For 20 C that gives 70 F (actual 68 F) — close enough for weather. Use the exact formula when precision matters.
Try it: Unit ConverterConvert temperature, length, mass, and more with exact results.Open tool
0 C— 32 F — water freezes20 C— 68 F — room temperature37 C— 98.6 F — body temperature100 C— 212 F — water boils
The scales meet at -40-40 C equals -40 F exactly. It is the one point where the two scales read the same number.