Temperature Conversion Formulas
Unlike length or weight, temperature scales don't share a zero point, so converting needs a formula rather than a single multiplier. Celsius sets 0° at water's freezing point; Fahrenheit sets it at a colder brine mixture, which is why the two disagree everywhere except −40°.
K = °C + 273.15 · °C = K − 273.15
Convert 180 °C (a common baking temperature) to Fahrenheit: 180 × 1.8 + 32 = 324 + 32 = 356 °F — which is why recipes say 350 °F.
Reference Temperatures
| Point | °C | °F | K |
|---|---|---|---|
| Absolute zero | −273.15 | −459.67 | 0 |
| Water freezes | 0 | 32 | 273.15 |
| Room temperature | 20–22 | 68–72 | ~294 |
| Body temperature | 37 | 98.6 | 310.15 |
| Water boils (sea level) | 100 | 212 | 373.15 |
| Oven, moderate | 180 | 356 | 453.15 |
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32: °F = °C × 1.8 + 32. So 25 °C = 77 °F. Quick mental version: double it, subtract 10%, add 32.
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9: °C = (°F − 32) ÷ 1.8. So 98.6 °F = 37 °C — normal body temperature.
What is the Kelvin scale?
The SI temperature scale starting at absolute zero (−273.15 °C), the coldest possible temperature. Kelvin uses the same step size as Celsius: K = °C + 273.15. There are no negative Kelvin temperatures.
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees. Setting C = F in the conversion formula gives −40 °C = −40 °F, the one point where the two scales cross.
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The CalculatorsGuide Editorial Team. (2026). Temperature Converter. CalculatorsGuide. Retrieved from https://www.calculatorsguide.com/conversions/temperature-converter/