Temperature Conversion Calculator
Convert temperatures between Celsius, Fahrenheit, and Kelvin using one convenient calculator. Temperature scales use different reference points and intervals, so each direction has its own formula. This tool helps avoid common conversion mistakes when comparing weather, laboratory, engineering, cooking, or scientific measurements.
Quick Answer
Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Celsius to Fahrenheit uses °F = (°C × 9/5) + 32. Fahrenheit to Celsius uses °C = (°F − 32) × 5/9. Kelvin conversions use an offset of 273.15.
Celsius, Fahrenheit, and Kelvin
Celsius is widely used for everyday temperature measurements and most countries use it for weather. Fahrenheit remains common in the United States. Kelvin is an absolute temperature scale used heavily in science and engineering.
Why the Formulas Are Different
Temperature scales do not share the same zero point or degree size. Celsius and Fahrenheit therefore require both a scale factor and an offset, while Kelvin and Celsius have equal-sized increments with a 273.15-degree offset.
Examples
0°C = 32°F = 273.15 K.
25°C = 77°F = 298.15 K.
100°C = 212°F = 373.15 K.
−40°C = −40°F.
Quick Reference
- Kelvin is written as K, not °K.
- Negative Celsius and Fahrenheit values are valid.
- Do not add or subtract 273.15 when converting directly between Fahrenheit and Kelvin without applying the scale conversion.