The degree Celsius (symbol: °C) can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature interval, a difference between two temperatures or an uncertainty. Before being renamed to honour Anders Celsius in 1948, the unit was called centigrade, from the Latin centum, which means 100, and gradus, which means steps.
| Definition | Relation to SI units |
|---|---|
[°C] ≡ [K] − 273.15 |
| degree Réaumur | degree Rømer | degree Fahrenheit | degree Celsius | degree Kelvin | degree Delisle | degree Newton | degree Rankine |
|---|---|---|---|---|---|---|---|
| 1 | 8.15625 | 34.25 | 1.25 | 274.4 | 148.125 | 0.4125 | 493.92 |
| -9.9047619 | 1 | 9.7142857 | -12.3809524 | 260.7690476 | 168.5714286 | -4.0857143 | 469.3842857 |
| -13.7777778 | -1.5416667 | 1 | -17.2222222 | 255.9277778 | 175.8333333 | -5.6833333 | 460.67 |
| 0.8 | 8.025 | 33.8 | 1 | 274.15 | 148.5 | 0.33 | 493.47 |
| -217.72 | -135.37875 | -457.87 | -272.15 | 1 | 558.225 | -89.8095 | 1.8 |
| 79.4666667 | 59.65 | 210.8 | 99.3333333 | 372.4833333 | 1 | 1 | 670.47 |
| 2.4242424 | 9.0909091 | 37.4545455 | 3.0303030 | 276.1803030 | 145.4545455 | 1 | 497.1245455 |
| -218.0755556 | -135.6120833 | -458.67 | -272.5944444 | 0.5555556 | 558.8916667 | -89.9561667 | 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
| 1 degrees Celsius | = 1 degrees Kelvin |
| 2 degrees Celsius | = 2 degrees Kelvin |
| 3 degrees Celsius | = 3 degrees Kelvin |
| 4 degrees Celsius | = 4 degrees Kelvin |
| 5 degrees Celsius | = 5 degrees Kelvin |