Fahrenheit to Celsius
Convert fahrenheit to celsius instantly. Change the amount or check the formula below.
Same temperature in three scales
°C≈ -6.666667 °C
°F= 20 °F
K≈ 266.483333 K
Temperature differences use a different rule: a change of 1 °C equals a change of 1 K or 1.8 °F. Do not add 32 when converting a temperature difference.
0 K is absolute zero. Conversion values are not a medical diagnosis. NIST temperature definitions.More actions
°C = (°F − 32) × 5/9
Same value in other units View equivalents
| Unit | Equivalent value |
|---|---|
| Celsius (°C) | -6.666667 °C |
| Kelvin (K) | 266.483333 K |
How to convert °F to °C
°C = (°F − 32) × 5/9
Enter your value in the converter. The displayed result updates immediately. All math is performed in your browser. You can use the copy function to save a result or share a linked example with a colleague.
Quick reference table
Choose a value below to try it in the live converter.
| Fahrenheit | Celsius |
|---|---|
| -40 °C | |
| -17.7777778 °C | |
| -6.6666667 °C | |
| 2.7777778 °C | |
| 37.7777778 °C |
Results use the temperature dimension. Choose compatible units only; the precision selector changes display rounding, not the underlying factor.
Verify °F to °C
Using the stated definitions, 1 °F ≈ -17.222222222 °C and 10 °F ≈ -12.222222222 °C. The live converter accepts your own value; the table provides additional check points.
Conversion method
°C = (°F − 32) × 5/9
Temperature scales include offsets
Absolute temperatures in Celsius, Fahrenheit and kelvin need an offset as well as a scale factor. A change of one Celsius degree is a change of 1.8 Fahrenheit degrees, but 1 °C is not 1.8 °F as an absolute temperature.
Negative Celsius or Fahrenheit values can be valid, but temperatures below absolute zero are not. The conversion engine validates the physical lower bound.
Need the other direction? Convert °C to °F.
Reference: NIST conversion factors. Calculation and display rounding are separate. See how we calculate.
Methodology: fixed SI definitions and standards-based factors. For safety-critical use, verify the required industry specification. Check definitions, conventions and sources.