Temperature Converter
Convert a temperature instantly between Celsius, Fahrenheit and Kelvin.
Conversion formulas
Celsius to Fahrenheit: °F = °C × 9/5 + 32. Celsius to Kelvin: K = °C + 273.15. This calculator converts your input to Celsius first, then derives all three scales from that single value, so the same formulas apply consistently no matter which unit you start from.
Quick reference points
- Water freezes at 0°C, 32°F, and 273.15 K
- Water boils at 100°C, 212°F, and 373.15 K (at sea level)
- Normal human body temperature is about 37°C, 98.6°F
- Absolute zero, the coldest theoretically possible temperature, is 0 K, -273.15°C, -459.67°F
Frequently asked questions
Why does Kelvin have no negative values or degree symbol?
Kelvin is an absolute temperature scale starting at absolute zero, the theoretical point where no further heat can be removed, so negative Kelvin values aren't physically meaningful. By convention it's also written without a degree symbol - simply "K", not "°K".
Which countries use Fahrenheit instead of Celsius?
Fahrenheit is mainly used in the United States and a few surrounding territories for everyday temperatures like weather forecasts, while Celsius is the standard nearly everywhere else in the world, including Saudi Arabia and the rest of the Gulf.
What happens if I enter a temperature below absolute zero?
The calculator will show an error, since a temperature below -273.15°C (0 K) is not physically possible under any known laws of physics.