Temperature is a fundamental measure of heat energy, but different regions use different scales. Here are the three main ones.
The Celsius Scale (°C)
Also called centigrade; widely used globally.
- Water freezes at 0°C
- Water boils at 100°C
- Room ~20–22°C
- Body ~37°C
The Fahrenheit Scale (°F)
Primarily used in the United States.
- Freeze 32°F
- Boil 212°F
- Room ~68–72°F
- Body ~98.6°F
The Kelvin Scale (K)
SI unit for temperature, used in science.
- Absolute zero 0 K (−273.15°C)
- Freeze 273.15 K
- Boil 373.15 K
- No degree symbol with K
Quick Conversion Guide
Formulas to convert between scales:
- °F → °C: (°F − 32) × 5/9
- °C → °F: (°C × 9/5) + 32
- °C → K: °C + 273.15
- K → °C: K − 273.15
Pro Tip
Estimate °F from °C: (°C × 2) + 30. Example: 20°C → ~70°F (actual 68°F).