Temperature Converter
Convert Celsius, Fahrenheit and Kelvin live in either direction
Choose the value and scales
Enter the temperature value first. Then select the source and target scales; use the swap button to reverse the conversion direction.
Factors and offsets
Celsius and Fahrenheit need both a factor and a 32-degree offset. Kelvin uses the Celsius interval but starts 273.15 below zero Celsius.
Useful examples
20 °C equals 68 °F and 293.15 K. In reverse, 212 °F equals 100 °C, while 0 K equals −273.15 °C.
Precision and limits
The result displays two decimals. Values below absolute zero are invalid, and extra digits cannot improve the accuracy of the original measurement.
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Multiply Celsius by 9/5 and add 32. For example, 20 °C becomes 68 °F.
How do I convert Fahrenheit to Celsius?
Subtract 32 and multiply the result by 5/9. For example, 212 °F becomes 100 °C.
What is Kelvin?
Kelvin is an absolute temperature scale. Zero kelvin is absolute zero, and a change of one kelvin is the same size as a change of one degree Celsius.
Why is temperature conversion not just multiplication?
Celsius and Fahrenheit use different interval sizes and different zero points, so their formulas need both a factor and an offset.
Which values are below absolute zero?
Values below −273.15 °C, −459.67 °F, or 0 K are below absolute zero and are rejected by this converter.
How many decimal places are useful?
Two decimal places are usually enough for everyday conversion. Measurement accuracy should determine whether more digits are meaningful.