°F to °C Converter
Convert °F to °C: °C = (°F − 32) × 5/9. Formula, worked example, table of common values and scale definitions.
Result40 °C
0 °F = -17.77777778 °C (scales with different zero points need a formula, not one factor)
104 °F =
40 °C
Formula
°C = (°F − 32) × 5/9 °F = °C × 9/5 + 32
Worked example
- °C = (°F − 32) × 5/9 with 104 °F gives 40 °C
Common values
| °F | °C |
|---|---|
| -40 | -40 |
| 32 | 0 |
| 68 | 20 |
| 86 | 30 |
| 104 | 40 |
| 140 | 60 |
| 194 | 90 |
| 212 | 100 |
Unit definitions
| Unit | Reference point | What it is |
|---|---|---|
| °F | 32 °F = 273.15 K | Degree Fahrenheit. A Fahrenheit degree is 5/9 of a kelvin. |
| °C | 0 °C = 273.15 K | Degree Celsius. 0 °C is the freezing point of water at standard pressure; the size of a degree equals one kelvin. |
Frequently asked questions
What is the formula to convert °F to °C?
°C = (°F − 32) × 5/9. To go back, °F = °C × 9/5 + 32.
At what temperature are Celsius and Fahrenheit equal?
At −40 °F, which is also −40 °C.
Related
Opposite direction: °C to °F
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