## Definitions

### Celsius degrees

Celsius degree °C is a unit for measuring temperatures according to the SI system of units. The Celsius scale of temperatures maps 0 degrees to the freezing point of water and 100 degrees to the boiling point of water. The theoretically lowest temperature in the Celsius scale is -273.15, called absolute zero temperature that describes the ultimately minimum point of atomic thermal motion. As a unit, Celsius degree °C is equal to the Kelvin degree °K, although their scales are different, since °K maps 0 to the absolute zero. When measuring temperature ranges however, both units are equal. It is acceptable to employ both units concurrently, although it is customary in many scientific fields to use °K for temperature intervals and °C for absolute temperature measurements.

Multiple and fraction units of temperature ranges in Celsius degrees can be defined through the decimal SI prefixes, as shown in next table. Their use however is not widespread.

Unit | Symbol | [°C] range |
---|---|---|

Nanodegrees Celsius | n°C | 10^{-9} |

Nanodegrees Celsius | μ°C | 10^{-6} |

Millidegrees Celsius | m°C | 0.001 |

Centidegrees Celsius | c°C | 0.01 |

Hectodegrees | h°C | 100 |

Kilodegrees | k°C | 1000 |

Megadegrees | M°C | 10^{6} |

### Fahrenheit degrees

Fahrenheit is a scale for the measurement of absolute temperatures. The Fahrenheit degree (symbol °F) is one step in the scale. The scale was originally defined through key physical temperatures such as human body temperature (≈96°F), freezing of water (32°F) and the stabilized temperature of a solution with equal parts of ice, water and salt (mapped to 0°F, this was probably the coldest material Daniel Gabriel Fahrenheit could produce in his laboratory). Today, the Fahrenheit scale is defined through two characteristic temperatures: freezing of water at 32°F and boiling of water at 212°F.

### How to convert degrees Celsius to Fahrenheit

- Multiply °C with 9/5 (=1.8)
- Add 32
- The result is the temperature in °F

### How to convert degrees Fahrenheit to Celsius

- Subtract 32 from °F
- Multiply with 5/9
- The result is the temperature in °C

### Key temperatures

In the following table some key temperatures are presented, both in [°F] and in [°C].

°C | °F | |
---|---|---|

Absolute zero | -273.15 | -459.67 |

Water freezing point | 0 | 32 |

Water boiling point | 100 | 212 |

Room temperature | 20 | 68 |

Human body temperature | 36.6 | 98 |

### Conversion table from [°C] to [°F]

In the following table some typical temperatures in degrees Celsius are converted to degrees Fahrenheit:

[°C] | [°F] |
---|---|

-50 | |

-20 | |

-10 | |

0 | |

5 | |

10 | |

15 | |

20 | |

25 | |

30 | |

50 | |

100 | |

200 |

### Conversion table from [°F] to [°C]

In the following table some typical temperatures in degrees Fahrenheit are converted to degrees Celsius:

[°F] | [°C] |
---|---|

-50 | |

-20 | |

-10 | |

0 | |

10 | |

20 | |

30 | |

40 | |

50 | |

60 | |

70 | |

80 | |

90 | |

100 | |

120 | |

150 | |

200 |