# Fahrenheit to Celsius converter

Converts degrees Fahrenheit (°F) to degrees Celsius (°C) and back, with the exact unit definitions.

- Page: https://www.acalculator.org/convert/fahrenheit-to-celsius
- JSON spec: https://www.acalculator.org/convert/fahrenheit-to-celsius.json
- Version: ac5d27214d4d

## Default answer

Example with the default inputs (Degrees Fahrenheit (°F) 98.6): 98.6 °F = 37 °C.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Degrees Fahrenheit (°F) | The amount in degrees Fahrenheit to convert. |
| result | Degrees Celsius (°C) | The same amount in degrees Celsius. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Degrees Fahrenheit (°F) | The amount in degrees Fahrenheit to convert. |
| result | Degrees Celsius (°C) | The amount in degrees Celsius. |

## Method

°C = (°F − 32) × 5 ÷ 9

## Assumptions

- Temperature scales have different zero points, so the conversion adds or subtracts as well as multiplies.
- The answer shows at most 6 decimal places; the calculation keeps full precision.

## Worked examples

1. value = 212 gives result = 100. Source: exact unit definitions in NIST SP 811 (2008), Appendix B.8.
2. value = 98.6 gives result = 37. Source: exact unit definitions in NIST SP 811 (2008), Appendix B.8.
3. result = 37 gives value = 98.6. Source: exact unit definitions in NIST SP 811 (2008), Appendix B.8.

## FAQ

### What is the formula to convert Fahrenheit to Celsius?

°C = (°F − 32) × 5 ÷ 9. For example, 98.6 °F is 37 °C.

### How do I convert Fahrenheit to Celsius?

Use °C = (°F − 32) × 5 ÷ 9. 98.6 °F gives 37 °C.

### How do I convert Celsius back to Fahrenheit?

Reverse the formula, or type the degrees Celsius into the second box and the converter works it out.

### At what temperature are Fahrenheit and Celsius equal?

At −40. −40 °F is −40 °C, because (−40 − 32) × 5 ÷ 9 = −40.

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B.8. https://www.nist.gov/pml/special-publication-811