Conversion formulas
Celsius → Fahrenheit: F = C × 9/5 + 32. Celsius → Kelvin: K = C + 273.15. Fahrenheit → Celsius: C = (F − 32) × 5/9.
When to use each scale
Celsius is used across most of the world. Fahrenheit is used mainly in the US. Kelvin is the scientific scale, used in physics and chemistry, where 0 K is absolute zero.
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32.
What is absolute zero?
It's 0 Kelvin, or -273.15°C, the lowest temperature theoretically possible.