Home › Temperature
Temperature converter
Celsius, Fahrenheit and Kelvin. The only common category where you cannot just multiply. 4 units, converted from one table of exact factors.
—
Worth knowing. These three scales do not just run at different speeds, they start in different places. That is why there is no single number you can multiply by — and why −40° is the one reading that is the same in Celsius and Fahrenheit.
1 celsius in every other temperature unit
Computed by the same engine that runs the converter above, so these can never drift apart from it.
| From | Equals | Unit |
|---|---|---|
| 1 celsius | 33.8 | fahrenheit (°F) |
| 1 celsius | 274.15 | kelvin (K) |
| 1 celsius | 493.47 | rankine (°R) |
What each unit actually is
Most converters give you a number and stop. Where a figure is exact by definition we say so, and where it is an average or shifts with conditions we say that too — that is usually the thing you needed to know.
| Unit | Symbol | What it actually is |
|---|---|---|
| celsius | °C | Water freezes at 0 and boils at 100 at sea level. Since 2019 it is defined from the kelvin. |
| fahrenheit | °F | Water freezes at 32 and boils at 212. −40° is the one temperature that reads the same in both scales. |
| kelvin | K | Absolute zero is 0 K. No degree sign, by convention. 0°C is 273.15 K exactly. |
| rankine | °R | Fahrenheit-sized degrees counted from absolute zero. Still used in some US engineering. |