Temperature Converter
Convert Celsius, Fahrenheit, Kelvin and Rankine.
25 °C
Celsius
77 °F
Fahrenheit
298.15 K
Kelvin
536.67 °R
Rankine
Formulas from Celsius: °F = °C × 9/5 + 32 · K = °C + 273.15 · °R = (°C + 273.15) × 9/5
Reference points
| Absolute zero | -273.15 °C | -459.67 °F | 0 K |
| Water freezes | 0 °C | 32 °F | 273.15 K |
| Room temperature | 21 °C | 69.8 °F | 294.15 K |
| Body temperature | 37 °C | 98.6 °F | 310.15 K |
| Water boils | 100 °C | 212 °F | 373.15 K |
About Temperature Converter
Temperature is the one everyday conversion that is not a simple multiplication, because Celsius and Fahrenheit disagree about where zero is as well as how big a degree is.
This converter handles all four scales at once, shows the formula it applied, and flags physically impossible values below absolute zero.
Frequently asked questions
Why is temperature conversion not a simple ratio?
Celsius and Fahrenheit have different zero points, so conversion needs both a scale factor and an offset.
What is absolute zero?
Minus 273.15 Celsius, or 0 Kelvin - the point where thermal motion is at a minimum. The converter warns if you go below it.
Where do the scales cross?
At minus 40 degrees, Celsius and Fahrenheit read the same number.