Celsius to Fahrenheit
°F = (°C × 9/5) + 32. Look up a Celsius reading in the chart or type any value, including negatives, for its Fahrenheit equivalent.
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Key Formula
°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9
Celsius → Fahrenheit
| °C | °F |
|---|---|
| -40 °C | -40.0 °F |
| -30 °C | -22.0 °F |
| -20 °C | -4.0 °F |
| -10 °C | 14.0 °F |
| -5 °C | 23.0 °F |
| 0 °C | 32.0 °F |
| 5 °C | 41.0 °F |
| 10 °C | 50.0 °F |
| 15 °C | 59.0 °F |
| 20 °C | 68.0 °F |
| °C | °F |
|---|---|
| 25 °C | 77.0 °F |
| 30 °C | 86.0 °F |
| 35 °C | 95.0 °F |
| 37 °C | 98.6 °F |
| 40 °C | 104.0 °F |
| 50 °C | 122.0 °F |
| 60 °C | 140.0 °F |
| 80 °C | 176.0 °F |
| 100 °C | 212.0 °F |
| 150 °C | 302.0 °F |
Reading a temperature in Fahrenheit? Convert °F to °C
How to convert Celsius to Fahrenheit
°F = °C × 9/5 + 32
9/5 is the same as 1.8: each Celsius degree spans 1.8 Fahrenheit degrees, and the 32 shifts the zero point.
25 °C
- 25 × 1.8 = 45
- 45 + 32 = 77 °F
−10 °C
- −10 × 1.8 = −18
- −18 + 32 = 14 °F
What is the Celsius scale?
The degree Celsius is defined through the kelvin, the SI unit of thermodynamic temperature: a Celsius temperature equals the kelvin value minus 273.15 (t/°C = T/K − 273.15), and a step of one degree Celsius is the same size as one kelvin.
The kelvin itself is fixed by setting the Boltzmann constant to exactly 1.380 649 × 10⁻²³ J/K, so Celsius readings trace back to a physical constant rather than to a particular thermometer.
Source: NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity or field of science (retrieved 2026-09-29) / BIPM — SI base unit: kelvin (retrieved 2026-09-29)
References
How the Celsius scale is anchored and where the conversion formula is published.
FAQ
37 × 1.8 + 32 = 98.6 °F.
40 × 1.8 + 32 = 104 °F.
30 × 1.8 + 32 = 86 °F.
Double the Celsius figure and add 30. It is exact at 10 °C and drifts by about 1 °F for every 5 °C away from that: 20 °C gives 70 °F against an exact 68 °F.