How to use this temperature converter
Enter the values requested in the fields above. The result updates instantly as you make changes, so you can compare scenarios without reloading the page. Use decimal values where appropriate and review the unit or calculation mode before interpreting the answer.
How the calculation works
Celsius and Kelvin have the same size degree, but their zero points differ by 273.15. Fahrenheit uses a different degree size: a change of 1°C equals a change of 1.8°F.
Temperature conversion includes both multiplication and an offset, unlike ordinary unit conversion. That is why doubling 10°C does not produce the Fahrenheit equivalent of doubling 50°F.
Formulas
Celsius to Fahrenheit
Fahrenheit to Celsius
Celsius to Kelvin
Worked examples
Room temperature
20°C converts to (20 × 9 ÷ 5) + 32 = 68°F.
Freezing point
0°C equals 32°F and 273.15 K under the standard conversion.
Common uses
Weather and travel
Translate a forecast between Celsius and Fahrenheit to compare unfamiliar conditions. Remember that temperature conversion changes the scale, not the underlying weather measurement or its uncertainty.
Cooking and climate control
Convert oven settings, recipe temperatures, thermostats, and equipment setpoints. Appliance calibration and permitted increments can matter more than extra decimal places in the converted result.
Science and education
Relate Celsius to kelvin for classroom and scientific work, and examine why Fahrenheit requires both scaling and an offset. Kelvin values are written without a degree symbol.
Accuracy and limitations
The calculator applies the standard linear relationships among Celsius, Fahrenheit, and kelvin. Values below absolute zero are rejected because they do not represent a physical thermodynamic temperature.
Converted digits should reflect the precision of the source reading. Medical, laboratory, industrial, and safety-critical temperatures require suitable calibrated instruments and the applicable procedure.
Frequently asked questions
Can Kelvin be negative?
No physical thermodynamic temperature is below 0 K, known as absolute zero. The tool flags results that would fall below it.
Why does Kelvin not use a degree symbol?
Kelvin is an SI base unit written as K, not °K.
Is the temperature converter free to use?
Yes. NumUtility is free, requires no account, and places no limit on ordinary calculations.
Are my entries stored?
No. The calculation runs in your browser. Values entered into the tool are not sent to NumUtility or saved by us.