Temperature conversion formulas
Temperature scales have different zero points, so you can't convert with a single multiplier. The formulas are:
- Celsius to Fahrenheit: °F = °C × 9/5 + 32 (37 °C = 98.6 °F)
- Fahrenheit to Celsius: °C = (°F − 32) × 5/9 (100 °F = 37.78 °C)
- Celsius to Kelvin: K = °C + 273.15
- Fahrenheit to Rankine: °R = °F + 459.67
Useful reference temperatures
| What | °C | °F |
|---|---|---|
| Absolute zero | −273.15 | −459.67 |
| Celsius and Fahrenheit are equal | −40 | −40 |
| Water freezes | 0 | 32 |
| Room temperature | 20–25 | 68–77 |
| Normal body temperature | 36.5–37.5 | 97.7–99.5 |
| Fever (adults) | 38 and above | 100.4 and above |
| Water boils (sea level) | 100 | 212 |
| Moderate oven | 180 | 356 (often rounded to 350) |
Temperature conversions
Each of these has its own page with the formula, worked examples and a full conversion table:
Degrees Celsius to degrees FahrenheitDegrees Fahrenheit to degrees CelsiusDegrees Celsius to kelvinKelvin to degrees CelsiusDegrees Fahrenheit to kelvinKelvin to degrees Fahrenheit
Frequently asked questions
What is 37 °C in Fahrenheit?
37 °C = 98.6 °F, the traditional normal body temperature.
At what temperature are Celsius and Fahrenheit the same?
At −40: −40 °C equals −40 °F.
Why is Kelvin written without “degrees”?
Kelvin is an absolute scale starting at absolute zero, and since 1967 its unit is simply the kelvin (K), not “degree Kelvin”. A change of 1 K equals a change of 1 °C.
What is 180 °C in Fahrenheit for baking?
180 °C = 356 °F. Recipes usually round it to 350 °F (gas mark 4).