Temperature Converter
Convert temperatures between Celsius, Fahrenheit and Kelvin instantly.
Temperature conversion formulas
To convert Celsius to Fahrenheit, multiply Celsius by 9/5 and add 32. To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9. Kelvin uses the same interval size as Celsius: Kelvin equals Celsius plus 273.15. Absolute zero is 0 K, equivalent to -273.15°C.
Worked examples
25°C to Fahrenheit: (25 × 9/5) + 32 = 77°F. 68°F to Celsius: (68 – 32) × 5/9 = 20°C. 0°C to Kelvin: 0 + 273.15 = 273.15 K.
Where temperature conversion is useful
Temperature conversion is useful when following international weather reports, recipes, scientific references, equipment specifications and travel information. Celsius is widely used for everyday temperatures in many countries, while Fahrenheit remains common in the United States. Kelvin is primarily used in scientific contexts.
Frequently asked questions
Is Kelvin written with a degree symbol?
No. Kelvin is written as K, not °K.
Why does Fahrenheit use different-sized values?
The Fahrenheit and Celsius scales use different zero points and interval sizes, which is why conversion requires both multiplication and an offset.
Can Kelvin be negative?
Ordinary thermodynamic Kelvin temperatures do not go below absolute zero, 0 K.
Why are results rounded?
The calculator limits displayed decimal places for readability while using the conversion formula on the entered value.
Related converter
For length, mass, area and volume measurements, use the Unit Converter.
Common temperature examples
0°C equals 32°F and 273.15 K. Likewise, 100°C equals 212°F. The calculator converts through the standard Celsius, Fahrenheit and Kelvin relationships.
About absolute zero
Kelvin is an absolute temperature scale and physical temperatures do not go below 0 K (−273.15°C or −459.67°F). Treat values below absolute zero as mathematically converted inputs, not physically valid temperatures.