Temperature Converter
20 °C is 68 °F or 293.15 K. A 350 °F oven is 176.7 °C.
How to use
- Enter a temperature and pick the scale it is in: Celsius, Fahrenheit, Kelvin or Rankine.
- The other three scales appear right away. Values below absolute zero are rejected.
- Choose how many decimal places to show, or use the reference table below for common temperatures such as body temperature and oven settings.
How it works
Every conversion goes through kelvin. K = °C + 273.15, °F = K × 9 ÷ 5 - 459.67 and °R = K × 9 ÷ 5.
The shortcut formulas follow from that: °F = °C × 9 ÷ 5 + 32 and °C = (°F - 32) × 5 ÷ 9. The two scales meet at -40, where -40 °C equals -40 °F.
Absolute zero is 0 K, which is -273.15 °C, -459.67 °F and 0 °R. Nothing can be colder, so any input that maps below it is flagged as an error.
Quick reference points
These pairs are computed with the same formulas as the converter. Oven settings are usually quoted in Fahrenheit in US recipes.
| Celsius | Fahrenheit | Kelvin |
|---|---|---|
| 0 °C | 32 °F | 273.15 K |
| 20 °C | 68 °F | 293.15 K |
| 37 °C | 98.6 °F | 310.15 K |
| 100 °C | 212 °F | 373.15 K |
| 180 °C | 356 °F | 453.15 K |
| 200 °C | 392 °F | 473.15 K |
FAQ
What is the difference between °R and K?
Both start at absolute zero. Kelvin uses the size of the Celsius degree, and Rankine uses the size of the Fahrenheit degree, so 1 K = 1.8 °R.
Is body temperature exactly 37 °C?
No. 37 °C (98.6 °F) is a widely used reference value. Normal body temperature varies between people and over the day, so treat it as a rough guide.
Is water boiling point exactly 100 °C?
Only roughly. About 100 °C at sea level under 1 atmosphere of pressure, and lower at altitude where air pressure is lower.
Why does the converter reject some numbers?
Any value that corresponds to less than 0 K, such as -300 °C, cannot exist physically, so no conversion is shown.