Convert a temperature between Celsius, Fahrenheit and Kelvin for weather, cooking and science.
Try an example
Load a ready-made sample into this tool and run it. Every result you see is calculated live by the tool itself — nothing here is a pre-written answer.
Sample: value: 100; from: C; to: F
How to Use
- Enter a temperature value.
- Choose the current scale and the target scale.
- Read the converted temperature.
What this temperature converter does
This temperature converter converts temperatures between the Celsius, Fahrenheit, and Kelvin scales. Enter a value, choose the scale it is in and the scale you need, and read the result. Weather reports, ovens, and scientific work each favour different scales depending on the country and the field, so converting keeps recipes, forecasts, and lab figures in the terms you understand.
The formulas behind the conversion
Fahrenheit is calculated from Celsius with the formula °F = °C × 9/5 + 32, which is why the scales meet only at minus 40. Kelvin starts at absolute zero and uses the same degree size as Celsius, so K = °C + 273.15. Those two relationships define every conversion this tool performs, in any direction between the three scales.
Good to know
Kelvin values below absolute zero, 0 K, are physically impossible and are rejected with an error rather than converted. The same applies to Celsius or Fahrenheit inputs that would land below 0 K. Everyday temperatures are unaffected; the check only stops values no real temperature can take.
Frequently asked questions
How do I convert 100 degrees Celsius to Fahrenheit?
Enter 100, convert from Celsius to Fahrenheit, and the result is 212 degrees, the boiling point of water at standard pressure. The formula multiplies by 9/5 and then adds 32.
What temperature is the same on Celsius and Fahrenheit?
Minus 40. It is the single point where the two scales cross, so −40 °C and −40 °F describe exactly the same temperature, a fact that makes a handy check of any conversion.
Why was my Kelvin value rejected?
Kelvin cannot go below zero, because 0 K is absolute zero, the lowest possible temperature. An input that would produce a negative Kelvin value returns an error instead of a meaningless result.
How to use Temperature Converter
- Enter a temperature value.
- Choose the current scale and the target scale.
- Read the converted temperature.
Limitations
Kelvin values below absolute zero (0 K) are physically impossible and are rejected with an error.