Temperature Converter: Celsius, Fahrenheit & Kelvin
Convert Celsius, Fahrenheit, and Kelvin with the formula shown for every conversion.
How the Temperature Converter works
Unlike length or weight, temperature scales have different zero points, so conversion needs an offset as well as a multiplier. Each result shows the formula used so you can check the working.
Kelvin is an absolute scale that starts at absolute zero (−273.15 °C), so it never has negative values. The tool rejects values below absolute zero.
Formulas used
- Celsius to Fahrenheit
°F = °C × 9/5 + 32- Fahrenheit to Celsius
°C = (°F − 32) × 5/9- Celsius to Kelvin
K = °C + 273.15
How to use the Temperature Converter in 3 steps
Step 1
Choose the temperature scale you are converting from.
Step 2
Type a temperature; every other scale updates immediately.
Step 3
Read the formula beside each result or copy the converted value.
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. For example, 20 °C × 1.8 + 32 = 68 °F.
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees. −40 °C is exactly −40 °F.