How to convert fahrenheit to celsius
Apply the documented fahrenheit-to-celsius relationship below, keeping the full stored constant until the displayed result is rounded.
°C = (°F − 32) × 5/9
For example, 10 °F equals -12.2222 °C.
Fahrenheit to Celsius reference table
| Fahrenheit | Celsius |
|---|---|
| 1 °F | -17.2222 °C |
| 5 °F | -15 °C |
| 10 °F | -12.2222 °C |
| 25 °F | -3.8889 °C |
| 50 °F | 10 °C |
| 100 °F | 37.7778 °C |
Method and quality checks
- Calculation
- °C = (°F − 32) × 5/9. The calculator keeps the stored factor through the operation and rounds only the displayed result to the selected or page-supported precision.
- Unit convention
- This is a point-temperature conversion, so the scale offset is included. Temperature intervals use a different rule.
- Input validation
- Finite numeric inputs are accepted, while values below absolute zero for the source scale are rejected.
- Reasonableness check
- 10 °F produces -12.2222 °C. Check the direction and approximate scale before relying on a more precise displayed value.
Deeper method: Temperature scales compared.
Reading Fahrenheit values on the Celsius scale
Fahrenheit and Celsius have different zero points and degree sizes. Subtract 32 from the Fahrenheit value, then multiply by 5/9. The result is an absolute temperature, not just a scaled interval.
- For a rough weather estimate, subtract 30 and divide by 2.
- Use the exact formula for ovens, laboratories, and technical limits.
- A change of 1 °F equals a change of 5/9 °C.
Reference: NIST: SI Units – Temperature.