Fahrenheit to Celsius and Celsius to Fahrenheit
Convert one temperature in either direction. Formula steps appear with the result.
Batch conversion · up to 100 lines
Uses the selected direction, mode, and rounding. Units on a line override direction.
Fahrenheit to Celsius and Celsius to Fahrenheit formulas
For an actual temperature, use °C = (°F − 32) ÷ 1.8. To go back, use °F = °C × 1.8 + 32. The offset matters because water freezes at 0 °C and 32 °F under standard conditions.
For a temperature change, omit the offset: a rise of 18 °F is a rise of 10 °C. Difference mode labels the result as a change. Do not use that mode to convert an oven setting, weather reading, or thermometer reading.
This is a unit converter, not a medical or food-safety assessment. It does not account for thermometer accuracy, oven fan settings, altitude, or cooking time.
Fahrenheit and Celsius conversion chart
Values below are actual temperatures, not temperature differences, rounded to four decimal places where needed.
| °F | °C |
|---|---|
| -40 | -40 |
| 0 | -17.7778 |
| 32 | 0 |
| 68 | 20 |
| 70 | 21.1111 |
| 72 | 22.2222 |
| 98.6 | 37 |
| 100 | 37.7778 |
| 212 | 100 |
| 350 | 176.6667 |
| 400 | 204.4444 |
| 450 | 232.2222 |
| 500 | 260 |
Rounding, pasted units, and batch copy
Choose the maximum number of decimal places for the result; unnecessary trailing zeros are removed. Calculations use browser floating-point arithmetic. A rounded display does not change the measurement's precision or uncertainty.
A unit suffix takes precedence over the direction selector. For example, 100 C always converts Celsius to Fahrenheit. A bare number uses the selected direction. Batch mode follows the same rules on every line and blocks copying until all non-empty lines are valid.
Inputs are limited to an absolute magnitude of one trillion. Empty fields clear the dependent result; unfinished entries such as a lone minus sign or an incomplete exponent need to be completed before conversion.
Frequently asked questions
How do I convert Fahrenheit to Celsius?
Subtract 32 from °F, then divide by 1.8. For example, 68 °F becomes (68 − 32) ÷ 1.8 = 20 °C.
How do I convert Celsius to Fahrenheit?
Multiply °C by 1.8, then add 32. For example, 100 °C becomes 212 °F. Choose the reverse direction or paste 100 C.
Is a change of 18 °F the same as an actual temperature of 18 °F?
No. A temperature increase of 18 °F is an increase of 10 °C. An actual temperature of 18 °F is about −7.78 °C. Use temperature difference mode for changes.
What is 350 °F in Celsius?
350 °F is approximately 176.67 °C. This is a numerical unit conversion, not a cooking-time or oven-fan adjustment.
Is 100 °F the same as 40 °C?
No. 100 °F is (100 − 32) ÷ 1.8, approximately 37.78 °C. A temperature of 40 °C equals 104 °F.
Can I enter a negative temperature?
Yes. Absolute temperatures may be negative in Celsius or Fahrenheit, but not below absolute zero: −273.15 °C or −459.67 °F. Temperature differences may be positive or negative.