Temperature Converter
Convert Celsius, Fahrenheit and Kelvin using the exact thermodynamic formulas.
Enter a temperature value and pick its current scale. Choose the scale you want and the converter applies the exact formula.
The formulas are: Celsius to Fahrenheit = (C × 9/5) + 32, Fahrenheit to Celsius = (F - 32) × 5/9, Celsius to Kelvin = C + 273.15, and Kelvin to Celsius = K - 273.15. Other pairs are computed by combining these two steps.
Use the swap button to reverse the direction, for example from Celsius to Fahrenheit and back.
Frequently asked questions
What is the formula for Celsius to Fahrenheit?
Multiply the Celsius value by 9/5, then add 32. For example, 20 °C becomes 68 °F.
How do you convert Fahrenheit to Kelvin?
Subtract 32, multiply by 5/9, then add 273.15. The converter does this automatically when you select those units.
Why is -40 °C equal to -40 °F?
It is the point where the two scales intersect. Solving C = (C × 9/5) + 32 gives C = -40, so the two values coincide.