Celsius to Fahrenheit
Convert Celsius to Fahrenheit instantly, or swap to convert Fahrenheit to Celsius.
Results are provided as is, for general information. Check anything important before relying on it. See the Terms of Use.
About this tool
Convert temperatures between Celsius (°C) and Fahrenheit (°F) for weather, cooking, travel or lab work. To convert Celsius to Fahrenheit, multiply by 9, divide by 5 and add 32. To convert Fahrenheit to Celsius, subtract 32, then multiply by 5 and divide by 9. Both formulas are exact; only the displayed answer is rounded. Negative temperatures are supported, and values below absolute zero (−273.15 °C or −459.67 °F) are rejected. Choose automatic precision or 0, 1, 2 or 4 decimal places. Swap direction to convert Fahrenheit to Celsius.
How it works
°F = °C × 9 ÷ 5 + 32 °C = (°F − 32) × 5 ÷ 9
Celsius and Fahrenheit have different zero points and different degree sizes (one °C is 1.8 °F), so converting scales the number and adds or subtracts an offset. Both formulas are exact; only the displayed answer is rounded.
| Question | Working | Answer |
|---|---|---|
| 20 °C in Fahrenheit | 20 × 9 ÷ 5 + 32 | 68 °F |
| 0 °C in Fahrenheit | 0 × 9 ÷ 5 + 32 | 32 °F |
| 37 °C in Fahrenheit | 37 × 9 ÷ 5 + 32 | 98.6 °F |
| 100 °F in Celsius | (100 − 32) × 5 ÷ 9 | 37.7778 °C |
When to use it
Questions
How do I convert Celsius to Fahrenheit?
Multiply the Celsius value by 9, divide by 5, then add 32. For example, 20 °C × 9 ÷ 5 + 32 = 68 °F. Multiplying by 1.8 instead of 9 ÷ 5 gives the same result.
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply by 5 and divide by 9. For example, 100 °F is (100 − 32) × 5 ÷ 9, approximately 37.7778 °C. Use Swap, then enter Fahrenheit to convert in this direction.
What is 37 °C in Fahrenheit?
37 °C is exactly 98.6 °F (37 × 9 ÷ 5 + 32). The converter only changes the scale of the number; it does not interpret what a reading means.
At what temperature are Celsius and Fahrenheit equal?
At −40. Setting °C equal to °F in the conversion formula gives −40 on both scales.
Why does the converter reject some low values?
Absolute zero, −273.15 °C or −459.67 °F, is the lowest temperature that can exist. The converter treats anything colder as an input error.
Is the conversion exact?
Yes. The formulas use exact fractions, so the only rounding comes from the number of decimal places you choose to display.