The formula
To convert Celsius to Fahrenheit, multiply the Celsius value by 9/5 and add 32: °F = (°C × 9/5) + 32.
Examples
0°C equals 32°F. 20°C equals 68°F. 100°C equals 212°F.
Why the calculation is different
Temperature scales have different zero points and increments, so temperature conversion is not a simple multiplication by a constant.
Celsius to Fahrenheit Formula
Celsius and Fahrenheit use different zero points, so this conversion requires both multiplication and an offset.
Worked Examples
- 0 °C = 32 °F.
- 20 °C = 68 °F.
- 37 °C = 98.6 °F.
- 100 °C = 212 °F.
Reverse Conversion
To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9.
Negative Temperatures
The formula also works for temperatures below 0 °C. For example, −10 °C corresponds to 14 °F. Check the sign carefully when entering negative values.
Rounding
Temperature results are often displayed to one or two decimal places. For weather, cooking and everyday use, follow the precision appropriate to the source measurement and application.
Use the Tervilo Temperature Converter
Use the Tervilo Temperature Converter for Celsius, Fahrenheit and Kelvin conversions.
The Celsius-to-Fahrenheit Formula
Celsius and Fahrenheit use different zero points and different temperature intervals. The standard conversion from Celsius to Fahrenheit is:
The multiplication by 9/5 changes the size of the temperature interval, while adding 32 accounts for the different zero points of the two scales.
Worked Examples
| Celsius | Fahrenheit |
|---|---|
| -40°C | -40°F |
| 0°C | 32°F |
| 20°C | 68°F |
| 37°C | 98.6°F |
| 100°C | 212°F |
Why -40 Is a Useful Check
-40 is the same numerical temperature on both Celsius and Fahrenheit scales. It provides a convenient sanity check for the conversion formula. If -40°C is entered, the correct result is -40°F.
Converting Negative Celsius Temperatures
The formula works for temperatures below zero as well as positive temperatures. Keep the negative sign attached to the Celsius value before multiplying by 9/5. Do not convert the absolute value and add the negative sign later unless the complete calculation has been handled correctly.
Rounding Temperature Results
The mathematical result can contain decimal places. Weather reports may normally display a whole number, while scientific, laboratory or technical applications may require greater precision. Round the final result rather than rounding an intermediate calculation.
Common Celsius-to-Fahrenheit Mistakes
- Adding 32 before multiplying by 9/5.
- Using the Fahrenheit-to-Celsius formula in the wrong direction.
- Forgetting the 32-degree offset.
- Dropping the negative sign from a temperature below zero.
- Rounding intermediate values unnecessarily.
Practical Uses
Celsius-to-Fahrenheit conversion is useful when comparing weather information, recipes, appliance settings, equipment specifications, laboratory notes and other information written using different temperature scales.
Use the Tervilo Celsius-to-Fahrenheit Converter
Enter the Celsius temperature in the Tervilo converter and review the Fahrenheit result. For calculations that will be used again, retain sufficient decimal precision before rounding the displayed answer.