Degrees Fahrenheit to Degrees Celsius
Type a value in Degrees Fahrenheit and get the result in Degrees Celsius, calculated exactly.
20 Degrees Fahrenheit ≈ −6.666666667 Degrees Celsius
Exact factorRounded for display to about 10 significant digits.
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Range -25 – 50 °F = -31.6667 – 10 °C
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Formula
°C = °F × 0.555555555556 + −17.7777777778
To convert Degrees Fahrenheit to Degrees Celsius, multiply the value by 0.555555555556, then add −17.7777777778.
Worked examples
- 0 °F ≈ −17.77777778 °C
- 20 °F ≈ −6.666666667 °C
- 100 °F ≈ 37.77777778 °C
This factor is exact by definition.
Conversion table
| Degrees Fahrenheit (°F) | Degrees Celsius (°C) |
|---|---|
| −40 | −40 |
| −30 | ≈ −34.44444 |
| −20 | ≈ −28.88889 |
| −10 | ≈ −23.33333 |
| 0 | ≈ −17.77778 |
| 5 | −15 |
| 10 | ≈ −12.22222 |
| 15 | ≈ −9.444444 |
| 20 | ≈ −6.666667 |
| 25 | ≈ −3.888889 |
| 30 | ≈ −1.111111 |
| 35 | ≈ 1.666667 |
| 37 | ≈ 2.777778 |
| 40 | ≈ 4.444444 |
| 50 | 10 |
| 60 | ≈ 15.55556 |
| 70 | ≈ 21.11111 |
| 80 | ≈ 26.66667 |
| 90 | ≈ 32.22222 |
| 100 | ≈ 37.77778 |
| 150 | ≈ 65.55556 |
| 200 | ≈ 93.33333 |
Values marked ≈ are rounded; the rest are exact.
Reverse table: Degrees Celsius to Degrees Fahrenheit
| Degrees Celsius (°C) | Degrees Fahrenheit (°F) |
|---|---|
| −40 | −40 |
| −30 | −22 |
| −20 | −4 |
| −10 | 14 |
| 0 | 32 |
| 5 | 41 |
| 10 | 50 |
| 15 | 59 |
| 20 | 68 |
| 25 | 77 |
| 30 | 86 |
| 35 | 95 |
| 37 | 98.6 |
| 40 | 104 |
| 50 | 122 |
| 60 | 140 |
| 70 | 158 |
| 80 | 176 |
| 90 | 194 |
| 100 | 212 |
| 150 | 302 |
| 200 | 392 |
Unit definitions
- Degrees Fahrenheit °F
- Water freezes at 32 °F and boils at 212 °F; one degree is 5/9 of a kelvin.
- Degrees Celsius °C
- The kelvin scale shifted by exactly 273.15: 0 °C is 273.15 K.
Questions people ask
Degrees Fahrenheit to Degrees Celsius: what is the conversion factor?
One °F is ≈ −17.22222222 °C.
How do I convert Degrees Fahrenheit to Degrees Celsius?
Use the formula above. For example, 20 °F = ≈ −6.666666667 °C.
Is the conversion exact?
Yes. Both units have exact definitions, so the factor is exact; a result is only rounded when its decimals never end.
Factors checked 19 October 2026.