21 Fahrenheit to Celsius
21 degrees Fahrenheit equals
-6.11°C
-6.11 degrees Celsius
21°F is -6.11°C, well below the point where water freezes. Roads ice over here, and this is where winter forecasts in northern climates spend most of the season. For reference, water freezes at 0°C, or 32°F.
How to convert 21°F to °C
Formula
°C = (°F − 32) × 5/9
Substituting 21°F
- 21 − 32 = -11
- -11 × 5/9 = -6.11
Fahrenheit places the freezing point of water at 32 rather than 0, so that offset comes off first. What remains is then scaled by 5/9, because a Celsius degree covers 1.8 times as much temperature change as a Fahrenheit degree.
How 21°F compares
| Reference point | Temperature | Difference |
|---|---|---|
| Freezing point of water | 0°C / 32°F | 6.1°C (11°F) colder |
| Room temperature | 21°C / 69.8°F | 27.1°C (48.8°F) colder |
| Body temperature | 37°C / 98.6°F | 43.1°C (77.6°F) colder |
| Boiling point of water | 100°C / 212°F | 106.1°C (191°F) colder |