Celsius to Fahrenheit Converter
Type a temperature into any box and the other two update as you type. It works both ways, so the same tool handles Fahrenheit to Celsius and Kelvin.
Formula
- °F = °C × 9/5 + 32
- °C = (°F − 32) × 5/9
- K = °C + 273.15
Results are calculated exactly and rounded to 2 decimal places for display. Values below absolute zero (0 K) are rejected.
Reference table
| Celsius (°C) | Fahrenheit (°F) | Kelvin (K) |
|---|---|---|
| -40 | -40 | 233.15 |
| -30 | -22 | 243.15 |
| -20 | -4 | 253.15 |
| -10 | 14 | 263.15 |
| -5 | 23 | 268.15 |
| 0 | 32 | 273.15 |
| 5 | 41 | 278.15 |
| 10 | 50 | 283.15 |
| 15 | 59 | 288.15 |
| 20 | 68 | 293.15 |
| 25 | 77 | 298.15 |
| 30 | 86 | 303.15 |
| 35 | 95 | 308.15 |
| 37 | 98.6 | 310.15 |
| 40 | 104 | 313.15 |
| 100 | 212 | 373.15 |
Good to know
- −40 is the one temperature that reads the same in Celsius and Fahrenheit.
- A quick mental estimate is to double the Celsius value and add 30. It is close around 10 °C and drifts further off at the extremes, so use the exact formula when it matters.