Fahrenheit to Celsius Converter
Convert °F to °C instantly, with charts for cooking and weather
°C = (°F − 32) × 5/9. Subtract 32 from the Fahrenheit temperature, then multiply by 5/9 (or divide by 1.8). For example, 68 °F = 20 °C and 350 °F = 176.67 °C.
How to convert Fahrenheit to Celsius
This is the Celsius to Fahrenheit formula run backwards. Fahrenheit's zero sits 32 degrees below the freezing point of water, so you first remove that offset by subtracting 32. What is left is a number of Fahrenheit degrees above freezing, and since 180 Fahrenheit degrees span the same range as 100 Celsius degrees, you multiply by 100/180, which is 5/9. The Celsius to Fahrenheit converter runs the same two steps in reverse, and the temperature converter shows one reading on all five scales at once.
Always subtract before you multiply. For 68 °F, 68 − 32 = 36 and 36 × 5/9 = 20 °C. Doing it the other way round, 68 × 5/9 − 32, gives 5.8 °C, which is badly wrong. If you only need a temperature difference, such as “the oven runs 25 °F hot”, skip the 32 and just multiply: 25 °F of difference is about 13.9 °C. If a lab calculation needs kelvin, convert to Celsius here first, then use the Celsius to kelvin converter.
Step by step
- Take the temperature in degrees Fahrenheit.
- Subtract 32.
- Multiply the result by 5/9 (or divide by 1.8).
- Round to one decimal for body temperature and cooking, or to a whole degree for weather.
See it on a scale
Worked examples
A 72 °F thermostat setting, the classic 98.6 °F body temperature, and a 350 °F oven from an American recipe.
°C = (72 − 32) × 5/9 = 22.222222
= 22.222222 °C
°C = (98.6 − 32) × 5/9 = 37
= 37 °C
°C = (350 − 32) × 5/9 = 176.66667
= 176.66667 °C
How hot is 100 degrees Fahrenheit in Celsius?
100 °F is 37.78 °C, a heat-wave temperature that sits just above normal human body temperature of 37 °C.
The working is (100 − 32) × 5/9 = 68 × 5/9 = 37.78 °C. As weather, it is serious heat, especially when the air is humid and sweat cannot evaporate. As a body temperature, it is raised but still below the 100.4 °F (38 °C) line that the CDC uses to define a fever.
Be careful with the phrase “100 degrees”, because it means very different things on different scales:
- 100 °F = 37.78 °C: a hot summer afternoon.
- 100 °C = 212 °F: water boiling at sea level.
- 100 K = −173.15 °C: far colder than any weather on Earth.
Every 10 °F step is worth 5.56 °C, so 110 °F desert heat is 43.33 °C and a 105 °F heat wave is 40.56 °C.
How do you convert a temperature change from Fahrenheit to Celsius?
Multiply the change by 5/9 and do not subtract 32: a rise of 18 °F is a rise of exactly 10 °C, and a 9 °F drop is a 5 °C drop.
The 32 in the full formula moves the zero point of the scale. A difference between two readings has no zero point to move, because each reading would lose the same 32 and the two cancel. So a difference needs only the 5/9 scale factor, which is the same as dividing by 1.8.
- A fever that climbs from 98.6 °F to 102.2 °F has risen 3.6 °F, which is 2 °C (37 °C to 39 °C).
- A forecast of “15 degrees colder tomorrow” in Fahrenheit is a drop of 8.33 °C.
- A thermostat that lets the room swing by 2 °F holds it within 1.11 °C.
- A sous-vide tolerance of ±0.5 °F is ±0.28 °C.
Running a change through the full formula gives nonsense: (18 − 32) × 5/9 = −7.78 °C, a negative “rise”.
Fahrenheit to Celsius conversion chart
Fahrenheit temperatures converted to Celsius and rounded to two decimal places, from winter lows through fever readings to oven heat.
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| -40 °F | -40 °C |
| -20 °F | -28.89 °C |
| -10 °F | -23.33 °C |
| 0 °F | -17.78 °C |
| 10 °F | -12.22 °C |
| 20 °F | -6.67 °C |
| 32 °F | 0 °C |
| 40 °F | 4.44 °C |
| 50 °F | 10 °C |
| 60 °F | 15.56 °C |
| 65 °F | 18.33 °C |
| 68 °F | 20 °C |
| 70 °F | 21.11 °C |
| 72 °F | 22.22 °C |
| 75 °F | 23.89 °C |
| 80 °F | 26.67 °C |
| 85 °F | 29.44 °C |
| 90 °F | 32.22 °C |
| 95 °F | 35 °C |
| 98.6 °F | 37 °C |
| 100 °F | 37.78 °C |
| 100.4 °F | 38 °C |
| 104 °F | 40 °C |
| 110 °F | 43.33 °C |
| 150 °F | 65.56 °C |
| 200 °F | 93.33 °C |
| 212 °F | 100 °C |
| 250 °F | 121.11 °C |
| 300 °F | 148.89 °C |
| 325 °F | 162.78 °C |
| 350 °F | 176.67 °C |
| 375 °F | 190.56 °C |
| 400 °F | 204.44 °C |
| 425 °F | 218.33 °C |
| 450 °F | 232.22 °C |
| 500 °F | 260 °C |
Fahrenheit vs Celsius: how do the two scales compare?
The Fahrenheit and Celsius scales describe the same physical temperatures with different zero points and different degree sizes. The top rows are generated from the exact definitions; the rows below add how and where each scale is used.
| Attribute | Fahrenheit | Celsius |
|---|---|---|
| Symbol | °F | °C |
| System | US customary | Metric (SI derived) |
| Defined as | °C × 9/5 + 32 | K − 273.15 |
| Water freezes at | 32 °F | 0 °C |
| Water boils at (1 atm) | 212 °F | 100 °C |
| Absolute zero | -459.67 °F | -273.15 °C |
| Original zero point | A freezing brine of ice, water and salt | The freezing point of water, after the scale was flipped in the 1740s |
| One whole-degree step | 0.5556 °C | 1.8 °F |
| Fever threshold (CDC) | 100.4 °F | 38 °C |
| Comfortable room | 68–72 °F | 20–22.2 °C |
| Main users today | The United States, plus a few places such as the Bahamas, Belize and the Cayman Islands | Almost every other country, and science and industry everywhere |
5 key differences
- Each Fahrenheit degree is 5/9 of a Celsius degree, so a 1 °F thermostat step moves the room by only 0.56 °C.
- The Fahrenheit zero lies 17.78 Celsius degrees below the Celsius zero, which is why 0 °F is −17.78 °C.
- Absolute zero is −459.67 °F but −273.15 °C, so deep-cold Fahrenheit readings run to much larger negative numbers.
- US oven dials step in 25 °F increments, which is 13.89 °C per step.
- Everyday weather from 0 °F to 100 °F spans −17.78 °C to 37.78 °C.
What are safe cooking temperatures in Celsius?
Cook poultry and leftovers to 73.9 °C, ground meat and egg dishes to 71.1 °C, and steaks, roasts, chops and fish to 62.8 °C: the USDA's Fahrenheit minimums, converted and rounded to one decimal. The USDA publishes safe minimum internal temperatures in Fahrenheit. Here they are in Celsius for digital thermometers set to metric. Measure in the thickest part of the food, away from bone. Oven settings for the same dishes are covered by the cooking converter.
| Food | USDA minimum | Celsius |
|---|---|---|
| Poultry (whole, pieces, ground) | 165 °F | 73.9 °C |
| Ground beef, pork, veal and lamb | 160 °F | 71.1 °C |
| Egg dishes | 160 °F | 71.1 °C |
| Leftovers and casseroles | 165 °F | 73.9 °C |
| Beef, pork, veal and lamb steaks, chops and roasts (then rest 3 minutes) | 145 °F | 62.8 °C |
| Fresh (raw) ham (then rest 3 minutes) | 145 °F | 62.8 °C |
| Fish and shellfish | 145 °F | 62.8 °C |
| Precooked ham, reheated | 140 °F | 60.0 °C |
Thermostat, weather and hot tub temperatures
US thermostats, weather apps and pool heaters show Fahrenheit. This chart gives the Celsius value for common settings, which helps when you travel or talk to someone who thinks in metric.
| Fahrenheit | Celsius | Context |
|---|---|---|
| 55 °F | 12.8 °C | Common setback temperature overnight or when away |
| 60 °F | 15.6 °C | Cool room |
| 65 °F | 18.3 °C | Cool but comfortable indoors |
| 68 °F | 20.0 °C | US Department of Energy winter setting while at home |
| 70 °F | 21.1 °C | Typical indoor comfort |
| 72 °F | 22.2 °C | Warm room; common office setting |
| 75 °F | 23.9 °C | Warm |
| 78 °F | 25.6 °C | US Department of Energy summer setting while at home |
| 85 °F | 29.4 °C | Hot summer day |
| 90 °F | 32.2 °C | Very hot |
| 95 °F | 35.0 °C | Heat wave |
| 100 °F | 37.8 °C | Extreme heat |
| 104 °F | 40.0 °C | Maximum hot tub temperature recommended by the CPSC |
| 110 °F | 43.3 °C | Desert heat |
Is there a quick way to convert Fahrenheit to Celsius?
Yes: subtract 30 and halve for a rough weather estimate, or subtract 32, halve, and add a tenth of that half for a result only about 1% low.
For a quick estimate, take 30 off the Fahrenheit number and halve what is left. It is the reverse of the “double it and add 30” trick. For 70 °F: 70 − 30 = 40, and half of 40 is 20 °C. The exact answer is 21.1 °C.
The shortcut is exact at 50 °F (10 °C) and drifts the further you go. At 100 °F it says 35 °C when the truth is 37.8 °C, and at 350 °F it is off by 16.7 °C, so never use it to set an oven.
A better mental method
Subtract 32, halve it, then add 10% of that half. Halving and adding a tenth multiplies by 0.55, very close to the exact 0.5556, so the result is about 1% low. For 350 °F: 350 − 32 = 318, half is 159, plus 15.9 is 174.9 °C, against an exact 176.67 °C.
Useful anchors
- 32 °F = 0 °C and 212 °F = 100 °C.
- 50 °F = 10 °C, 68 °F = 20 °C, 86 °F = 30 °C: every 18 °F is 10 °C.
- 98.6 °F = 37 °C and 100.4 °F = 38 °C, the fever line.
- 350 °F ≈ 180 °C, the moderate oven of most recipes.
How far off is “subtract 30 and halve”?
The quick estimate compared with the exact formula. A minus sign means the shortcut reads too cold. It is best for everyday weather and poor for anything hot.
| Fahrenheit | Exact Celsius | Subtract 30, halve | Error |
|---|---|---|---|
| 0 °F | −17.8 °C | −15 °C | +2.8 °C |
| 32 °F | 0 °C | 1 °C | +1 °C |
| 40 °F | 4.4 °C | 5 °C | +0.6 °C |
| 50 °F | 10 °C | 10 °C | 0 °C |
| 60 °F | 15.6 °C | 15 °C | −0.6 °C |
| 70 °F | 21.1 °C | 20 °C | −1.1 °C |
| 80 °F | 26.7 °C | 25 °C | −1.7 °C |
| 90 °F | 32.2 °C | 30 °C | −2.2 °C |
| 100 °F | 37.8 °C | 35 °C | −2.8 °C |
| 212 °F | 100 °C | 91 °C | −9 °C |
| 350 °F | 176.7 °C | 160 °C | −16.7 °C |
| 450 °F | 232.2 °C | 210 °C | −22.2 °C |
Why does the US still use Fahrenheit?
Because the US never made the switch to metric compulsory. The Metric Conversion Act of 1975 set up a voluntary changeover, and weather reports, home cooking and household thermometers stayed with the familiar Fahrenheit scale.
Daniel Gabriel Fahrenheit, an instrument maker born in Danzig (now Gdańsk, Poland) who worked in the Netherlands, published his scale in 1724. It spread through the British Empire and was the standard in Britain and its colonies for two centuries. From the 1960s most English-speaking countries switched to Celsius as part of metrication. The United States kept Fahrenheit for weather, cooking and medicine, and a handful of places such as the Bahamas, Belize and the Cayman Islands still use it in daily life.
American science, engineering and medicine research use Celsius and kelvin, so a US scientist may read 72 °F on the thermostat and write 22 °C in the lab notebook. Fans of Fahrenheit point out that its degrees are smaller, so whole numbers give finer steps, and that 0 to 100 °F roughly spans the range of weather people live in. Supporters of Celsius value its neat link to water and to the metric system. Either way, converting is just two steps: subtract 32, multiply by 5/9. For other US-to-metric everyday conversions, see the pounds to kg converter.
Sources and further reading
The standards and references behind the numbers on this page. Links open in a new tab.
Standards and official sources
Further reading
- Degree FahrenheitWikipedia
- Degree CelsiusWikipedia
Fahrenheit to Celsius FAQs
Short, exact answers to what people ask most.
How do you convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9 (or divide by 1.8). For example, 86 °F − 32 = 54, and 54 × 5/9 = 30 °C.
What is 98.6 °F in Celsius?
98.6 °F is exactly 37 °C, the traditional value for normal body temperature. A reading of 100.4 °F (38 °C) or higher is generally treated as a fever.
What is 350 °F in Celsius?
350 °F is 176.67 °C. Recipes normally round it to 180 °C, or about 160 °C for a fan oven.
What is 72 °F in Celsius?
72 °F is 22.22 °C, a common indoor thermostat setting. 70 °F is 21.11 °C and 75 °F is 23.89 °C.
Why do you subtract 32 before multiplying?
Because the 32 is an offset in Fahrenheit degrees: water freezes at 32 °F but 0 °C. You must remove it while the number is still in Fahrenheit, then rescale by 5/9 to get Celsius.
What is 0 °F in Celsius?
0 °F is −17.78 °C, well below freezing. It is a very cold winter day, and it is where Fahrenheit originally set the zero of his scale using a brine mixture.
What is 400 °F in Celsius?
400 °F is 204.44 °C, a hot oven for roasting vegetables and baking bread. Recipes round it to 200 °C, or about 180 °C in a fan oven.
What is 90 °F in Celsius?
90 °F is 32.22 °C, a very hot summer day. It is 58 Fahrenheit degrees above freezing, and 58 × 5/9 = 32.22.
What is 60 °F in Celsius?
60 °F is 15.56 °C, a cool spring or autumn day when a light jacket is comfortable.
Related conversions
Conversion formula from NIST SP 811 (2008), Appendix B; safe minimum internal temperatures from the USDA Food Safety and Inspection Service; thermostat settings from the US Department of Energy; hot tub guidance from the US Consumer Product Safety Commission; fever threshold of 100.4 °F (38 °C) per the US Centers for Disease Control and Prevention; US metric policy from the Metric Conversion Act of 1975. Last updated . How we verify our numbers.