How to convert temperatures
- Enter the temperature.
- Choose the scale you have in From and the one you need in To: Celsius, Fahrenheit or Kelvin.
- Read the converted value, the formula used and the same temperature in all three scales.
The formulas
Temperature scales have different zero points, so you cannot convert by multiplying alone. The tool uses explicit formulas:
| From | To | Formula |
|---|---|---|
| Celsius | Fahrenheit | °F = °C × 9/5 + 32 |
| Fahrenheit | Celsius | °C = (°F − 32) × 5/9 |
| Celsius | Kelvin | K = °C + 273.15 |
| Fahrenheit | Kelvin | K = (°F − 32) × 5/9 + 273.15 |
Fahrenheit degrees are smaller than Celsius degrees. A change of 1 °C equals a change of 1.8 °F, which is why the formula multiplies by 9/5.
Worked example
A recipe asks for an oven at 180 °C. What is that in Fahrenheit and Kelvin?
- Fahrenheit: 180 × 9/5 = 324, plus 32 gives 356 °F.
- Kelvin: 180 + 273.15 = 453.15 K.
Ovens are marked in round steps, so 356 °F is set as 350 °F in practice, which is within 6 degrees.
Fixed points worth knowing
| Event | °C | °F | K |
|---|---|---|---|
| Absolute zero | −273.15 | −459.67 | 0 |
| Water freezes | 0 | 32 | 273.15 |
| Normal body temperature | 37 | 98.6 | 310.15 |
| Water boils (sea level) | 100 | 212 | 373.15 |
Checks the tool makes
If you enter a value below absolute zero, such as −300 °C, the tool tells you instead of returning a number that cannot exist. Numbers are shown with up to ten significant digits, so a conversion like 100 °F to Celsius reads 37.77777778.
Popular pairs
Open Celsius to Fahrenheit or Fahrenheit to Celsius for a table of common values. For cooking amounts, the volume converter converts cups and milliliters, and the weight converter handles ounces and grams.
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