21°C in °F
21°C is 69.8°F. To convert Celsius to Fahrenheit, multiply by 1.8, then add 32.
Formula from NIST.
Show the workings
| Step | Sum | Answer |
|---|---|---|
| Multiply by 1.8 | 21 × 1.8 | 37.8 |
| Add 32 | 37.8 + 32 | 69.8 °F |
Where the figures come from
- Fahrenheit reading at the freezing point used in the conversion: 32 °F. Source: NIST Guide to the SI, Appendix B.9: factors for units listed by kind of quantity. Checked 14 November 2026.
- Fahrenheit degrees in one Celsius degree: 1.8. Source: NIST Guide to the SI, Appendix B.9: factors for units listed by kind of quantity. Checked 14 November 2026.
Nearby temperatures
| °C | °F |
|---|---|
| 5°C | 41°F |
| 10°C | 50°F |
| 15°C | 59°F |
| 16°C | 60.8°F |
| 18°C | 64.4°F |
| 20°C | 68°F |
| 21°C | 69.8°F |
| 22°C | 71.6°F |
| 23°C | 73.4°F |
| 24°C | 75.2°F |
| 25°C | 77°F |
| 26°C | 78.8°F |
| 27°C | 80.6°F |
How to convert Celsius to Fahrenheit
The US National Institute of Standards and Technology gives the conversion as °C = (°F − 32) ÷ 1.8. So to go from °C to °F, multiply by 1.8, then add 32. For example, 21°C is 698°F.. See NIST's table.
The two scales meet at −40, where −40°C and −40°F are the same temperature.