Temperature Converter
Temperature converter for Celsius, Fahrenheit, Kelvin and Rankine, with oven settings and the reference points that let you sanity-check a result.
Most used temperature tools
Celsius to Fahrenheit
The main tool, with oven presets from 180 °C and gas marks already worked out.
Oven Temperature Chart
Celsius, Fahrenheit, gas mark and fan in one table.
Cooking Conversions
Cups, grams and ounces for the same recipe.
Convert every scale at once
Enter a number.
Every temperature converter on this site
Reference table
| Celsius | Fahrenheit | Kelvin | Reference point |
|---|---|---|---|
| -273.15 °C | -459.67 °F | 0 K | absolute zero |
| -40 °C | -40 °F | 233.15 K | scales cross |
| 0 °C | 32 °F | 273.15 K | water freezes |
| 20 °C | 68 °F | 293.15 K | room temperature |
| 37 °C | 98.6 °F | 310.15 K | body temperature |
| 100 °C | 212 °F | 373.15 K | water boils at sea level |
| 180 °C | 356 °F | 453.15 K | common oven setting |
| 200 °C | 392 °F | 473.15 K | hot oven |
How the scales relate
Celsius and Fahrenheit are both offset scales, which is why converting between them needs an addition as well as a multiplication. Kelvin and Rankine are absolute scales, starting at absolute zero, so they need only the offset removed.
K = °C + 273.15
°R = K × 9/5
All four relationships are exact by definition. Minus 40 is the one temperature where Celsius and Fahrenheit read the same, which is a useful sanity check on any converter.
Which scale is used where
Celsius is standard almost everywhere and in science. Fahrenheit remains in everyday use in the United States. Kelvin is the SI base unit and is used in physics and engineering. Rankine is Fahrenheit's absolute counterpart and turns up mainly in some American thermodynamics work.
Common questions
Which temperature scale should I use?
Celsius for everyday use almost everywhere and in cooking, Fahrenheit in the United States, and Kelvin in science and engineering. Rankine is Fahrenheit's absolute counterpart and is rare outside some American thermodynamics work.
At what temperature do Celsius and Fahrenheit read the same?
Minus 40. That is the single point where the two scales cross, and it is a useful sanity check on any temperature converter.
Why does Kelvin not use a degree symbol?
Because it is an absolute scale measured from absolute zero rather than from an arbitrary reference point, so a kelvin is a unit of interval rather than a degree on a scale. It is written as 300 K, not 300 °K.
Is the Celsius to Fahrenheit conversion exact?
Yes. F = C times 9/5 plus 32 is a definitional relationship, not a measured factor, so it is exact at any precision.
Sources
- NIST Guide to the SI, Appendix B: Conversion Factors. National Institute of Standards and Technology. Source for every conversion factor used by this tool, and for which factors are exact rather than rounded.