Fahrenheit to Celsius Converter
Type a temperature in degrees Fahrenheit and get the Celsius value straight away, with kelvin as a bonus line. This is the Fahrenheit-first direction: it is built for the moment you meet an American oven setting, weather forecast or thermometer reading and want the Celsius figure you know. The page shows the subtraction and the 5/9 step with your own numbers.
Last updated November 4, 2026
Any value from -459.67 (absolute zero) upward. Decimals are fine.
Result
98.6 °F = 37 °C
| Scale | Temperature |
|---|---|
| Celsius | 37 °C |
| Kelvin | 310.15 K |
Show the work
Formula: °C = (°F - 32) × 5/9
- Start with the Fahrenheit value: 98.6 °F.
- Subtract 32: 98.6 - 32 = 66.6.
- Multiply by 5/9: 66.6 × 5/9 = 37.
- Kelvin, for reference: 37 + 273.15 = 310.15 K.
Result: 98.6 °F = 37 °C
The Fahrenheit to Celsius formula
°C = (°F − 32) × 5/9 (the same as (°F − 32) ÷ 1.8)
Subtract 32 first, then multiply by 5/9. The order matters. The Fahrenheit scale puts the freezing point of water at 32 degrees, while the Celsius scale puts it at 0. Subtracting 32 moves the zero point to the same place on both scales. Only then can you rescale the size of the degree.
The rescaling factor comes from the two reference points. Water freezes at 32 °F and boils at 212 °F under standard atmospheric pressure, a span of 180 Fahrenheit degrees. On the Celsius scale the same span is 0 to 100, which is 100 degrees. So one Fahrenheit degree is 100/180, or 5/9, of a Celsius degree. That is why the second step multiplies by 5/9, about 0.5556.
The conversion is exact, not an approximation. Kelvin, shown as a secondary line, is the Celsius value plus 273.15. Absolute zero is 0 K, which equals −273.15 °C or −459.67 °F. Nothing can be colder, so the converter rejects anything below −459.67 °F and says why.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Also useful alongside this calculator: MPG Calculator and Pace Calculator.
A quick mental shortcut
For a rough Celsius figure without a calculator, subtract 30 and halve the result. For 70 °F that gives 40, then 20, against an exact 21.1 °C. The error grows as temperatures rise, because the true multiplier is 0.5556 and not 0.5, so use the shortcut for weather and not for cooking or lab work.
Oven settings and weather in Fahrenheit
American recipes give oven temperatures in Fahrenheit, and most other countries set ovens in Celsius. A 350 °F recipe is 176.67 °C, which most Celsius ovens round to 175 or 180 °C. A 400 °F setting is 204.44 °C, usually rounded to 200 °C. Gas marks and fan ovens add further adjustments, so treat the converted figure as a starting point and check your oven manual.
For weather, 32 °F is freezing, 50 °F is a cool 10 °C, 68 °F is a comfortable 20 °C, and 86 °F is a hot 30 °C. A fever is usually counted from about 100.4 °F, which is 38 °C. This page only does the arithmetic; it is not medical advice.
Below zero and the −40 point
The formula works unchanged below zero. For 0 °F, subtract 32 to get −32, then multiply by 5/9 to get −17.78 °C. For −40 °F the subtraction gives −72 and the multiplication gives −40 °C. The two scales show the same number at exactly −40, and nowhere else.
How this differs from the Celsius to Fahrenheit page
This page starts from Fahrenheit and ends in Celsius. If you need the opposite direction, use the Celsius to Fahrenheit Converter, and for all three scales at once use the Temperature Converter. Both are linked under related calculators below.
How to use the Fahrenheit to Celsius Converter
- Type the temperature in degrees Fahrenheit into the box. Decimals and negative values are fine, down to −459.67.
- Read the Celsius result in the headline, with the kelvin value below it.
- Open Show the work to see the subtraction of 32 and the 5/9 multiplication with your own numbers.
- Compare with the table of common temperatures below as a sanity check.
- Use Copy, Print or Share to keep the result.
Worked example: 98.6 °F and other common points
Take the traditional body temperature of 98.6 °F. Subtract 32: 98.6 − 32 = 66.6. Multiply by 5/9: 66.6 × 5/9 = 37. So 98.6 °F is 37 °C. The same two steps give every row of the table, including a 350 °F oven, which is 318 × 5/9 = 176.6667 °C.
| Point | °F | °C |
|---|---|---|
| Equal point of both scales | -40 | -40 |
| Zero Fahrenheit | 0 | -17.7778 |
| Water freezes | 32 | 0 |
| Cool day | 50 | 10 |
| Room temperature | 68 | 20 |
| Warm day | 77 | 25 |
| Normal body temperature | 98.6 | 37 |
| Hot day | 104 | 40 |
| Water boils at sea level | 212 | 100 |
| Moderate oven | 350 | 176.6667 |
Frequently asked questions
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For 77 °F that is 77 − 32 = 45, and 45 × 5/9 = 25 °C.
What is 0 degrees Fahrenheit in Celsius?
It is about −17.78 °C. The formula gives 0 − 32 = −32, and −32 × 5/9 is −17.7778, a hard frost by any measure.
Why do you subtract 32 before multiplying by 5/9?
Because the scales start at different points: water freezes at 32 °F and 0 °C. Subtracting 32 aligns the zero points before the degree size is rescaled.
What is 350 degrees Fahrenheit in Celsius for baking?
Exactly 176.67 °C. Most Celsius ovens do not have that setting, so recipes round it to 175 or 180 °C depending on the oven.
Why does the converter refuse very low temperatures?
Nothing can be colder than absolute zero, which is −459.67 °F or −273.15 °C. Any lower Fahrenheit value is physically impossible, so it is rejected with a message.