°C, °F and Kelvin
Enter a temperature and choose the scales to convert between. Unlike most units, temperature scales have different zero points, so the conversion isn't a simple multiplication: °F = °C × 9/5 + 32 and K = °C + 273.15.
Useful for reading a thermometer in Fahrenheit, following an American recipe, or working with Kelvin in science.
How to convert temperature
- 1
Enter the temperature
Negative values are fine.
- 2
Choose the scales
Celsius, Fahrenheit or Kelvin.
- 3
Read the result
And all three scales in the table.
Key features
Three scales
°C, °F and K.
Exact formulas
No rounding.
Negative temperatures
Handled correctly.
All scales at once
See every conversion.
Common uses
- Health: Fever readings in °F to °C.
- Cooking: Oven temperatures from US recipes.
- Science: Kelvin for physics and chemistry.
Reference temperatures
| Point | °C | °F |
|---|---|---|
| Water freezes | 0 | 32 |
| Room temperature | 25 | 77 |
| Normal body temperature | 37 | 98.6 |
| Fever | 38 | 100.4 |
| Water boils (sea level) | 100 | 212 |
Tips and good to know
- A quick mental estimate: °F ≈ °C × 2 + 30 (close for everyday temperatures).
- Kelvin has no degree sign and can't go below 0 K (−273.15 °C).
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. 37 °C × 1.8 + 32 = 98.6 °F.
How do I convert Fahrenheit to Celsius?
Subtract 32 and multiply by 5/9. 100.4 °F − 32 = 68.4 × 5/9 = 38 °C.
What is −40 in Fahrenheit?
−40 °F. It's the one temperature where both scales match.