---
title: "21 °F to °C = -6.111111 °C"
description: "21 degrees Fahrenheit is -6.111111 degrees Celsius. The arithmetic, a table of nearby values, and a converter for any other number."
url: https://atoneplace.net/convert/21-fahrenheit-to-celsius/
site: "At One Place"
---

# 21 °F to °C

**21 degrees Fahrenheit in degrees Celsius: 21 °F = -6.111111 °C**

°C = (°F − 32) × 5/9

21 degrees Fahrenheit is -6.111111 degrees Celsius. To get there, use °C = (°F − 32) × 5/9.

## Values either side

*Degrees Fahrenheit near 21, converted to degrees Celsius.*

| Degrees Fahrenheit | Degrees Celsius |
| --- | --- |
| 17 °F | -8.333333 |
| 18 °F | -7.777778 |
| 19 °F | -7.222222 |
| 20 °F | -6.666667 |
| 21 °F ← | -6.111111 |
| 22 °F | -5.555556 |
| 23 °F | -5 |
| 24 °F | -4.444444 |
| 25 °F | -3.888889 |

## How the conversion works

The relationship is °C = (°F − 32) × 5/9. Both units measure temperature, so the conversion is a fixed formula that never changes. Temperature scales are the one common case where converting is not just multiplication — Celsius and Fahrenheit each put their zero in a different place, so an offset is applied as well as a scale factor.

## Common questions

### What is 21 °F in degrees Celsius?

21 °F is -6.111111 °C.

### How do you convert degrees Fahrenheit to degrees Celsius?

Use °C = (°F − 32) × 5/9.

## Related pages

- [Degrees Fahrenheit to degrees Celsius](https://atoneplace.net/convert/fahrenheit-to-celsius/)
- [21 °C to °F](https://atoneplace.net/convert/21-celsius-to-fahrenheit/)
- [17 °F to °C](https://atoneplace.net/convert/17-fahrenheit-to-celsius/)
- [18 °F to °C](https://atoneplace.net/convert/18-fahrenheit-to-celsius/)
- [19 °F to °C](https://atoneplace.net/convert/19-fahrenheit-to-celsius/)
- [20 °F to °C](https://atoneplace.net/convert/20-fahrenheit-to-celsius/)
- [22 °F to °C](https://atoneplace.net/convert/22-fahrenheit-to-celsius/)
- [23 °F to °C](https://atoneplace.net/convert/23-fahrenheit-to-celsius/)
- [24 °F to °C](https://atoneplace.net/convert/24-fahrenheit-to-celsius/)
- [25 °F to °C](https://atoneplace.net/convert/25-fahrenheit-to-celsius/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)