66 Fahrenheit to Celsius
66 degrees Fahrenheit equals
18.89°C
18.89 degrees Celsius
66°F equals 18.89°C, comfortable indoor temperature. Most thermostats are set somewhere in this band, and it is the standard range for storing and testing many household products.
How to convert 66°F to °C
Formula
°C = (°F − 32) × 5/9
Substituting 66°F
- 66 − 32 = 34
- 34 × 5/9 = 18.89
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 66°F compares
| Reference point | Temperature | Difference |
|---|---|---|
| Freezing point of water | 0°C / 32°F | 18.9°C (34°F) warmer |
| Room temperature | 21°C / 69.8°F | 2.1°C (3.8°F) colder |
| Body temperature | 37°C / 98.6°F | 18.1°C (32.6°F) colder |
| Boiling point of water | 100°C / 212°F | 81.1°C (146°F) colder |