Fahrenheit to Celsius Converter
To convert Fahrenheit to Celsius, use the formula C = (F - 32) × 5/9. For example, 25 Fahrenheit equals -3.888888889 Celsius. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
C = (F - 32) × 5/9
Use the temperature formula to convert Fahrenheit values to Celsius.
Example Conversions
0 Fahrenheit (F)
-17.77777778 Celsius (C)
1 Fahrenheit (F)
-17.22222222 Celsius (C)
25 Fahrenheit (F)
-3.888888889 Celsius (C)
100 Fahrenheit (F)
37.77777778 Celsius (C)
212 Fahrenheit (F)
100 Celsius (C)
Conversion Table
| Fahrenheit (F) | Celsius (C) |
|---|---|
| 0 | -17.77777778 |
| 1 | -17.22222222 |
| 10 | -12.22222222 |
| 20 | -6.666666667 |
| 25 | -3.888888889 |
| 32 | 0 |
| 37 | 2.777777778 |
| 50 | 10 |
| 75 | 23.88888889 |
| 100 | 37.77777778 |
| 212 | 100 |
| 273.15 | 133.9722222 |
How to Convert Manually
Use these steps to convert Fahrenheit values to Celsius without the calculator.
- Write down the value in Fahrenheit (F) that you want to convert.
- Apply the formula: C = (F - 32) × 5/9.
- For example, converting 10 Fahrenheit gives -12.22222222 Celsius.
- Label the result as Celsius (C).
About Fahrenheit and Celsius
The degree Fahrenheit sets water's freezing point at 32 °F and boiling point at 212 °F, dividing the interval into 180 degrees. The US uses it for weather, cooking, and medicine. The degree Celsius is the SI temperature unit for everyday use, with 0 °C at the freezing point and 100 °C at the boiling point of water at standard pressure. It is offset from the kelvin by exactly 273.15. The two scales are related by the formula C = (F - 32) × 5/9, not a fixed factor. Fahrenheit to Celsius conversion comes up most often in US weather forecasts and thermostats and in US oven and recipe temperatures, typically when figures need restating for weather forecasts outside the US.
Precision and Rounding: Temperature conversions are formula-based, not factor-based, so apply the full formula before rounding. Whole degrees are fine for weather and cooking; lab work, medicine, and HVAC commissioning usually carry one or two decimal places.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 Fahrenheit equals -9.444444444 Celsius.
15 F -> -9.444444444 C
FAQ
How do I convert Fahrenheit to Celsius?
Use the temperature formula to convert Fahrenheit values to Celsius.
What is the formula for Fahrenheit to Celsius?
The formula is C = (F - 32) × 5/9.
How many Celsius are in 1 Fahrenheit?
1 Fahrenheit equals -17.22222222 Celsius.
Can I convert Celsius back to Fahrenheit?
Yes. 1 Celsius equals 33.8 Fahrenheit, and the related converter can reverse the calculation.
What are common names for Fahrenheit and Celsius?
Fahrenheit is shown as F and may also be searched as fahrenheit, °F. Celsius is shown as C and may also be searched as celsius, centigrade, °C.
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