Updated September 2026
Fahrenheit to Celsius
Instantly convert fahrenheit to celsius with fast, accurate, real-time results.
Contents
If you're reading a US weather forecast, following an American recipe, or interpreting a temperature in Fahrenheit, this Fahrenheit to Celsius converter gives you the metric answer instantly. For the reverse direction, visit our Celsius to Fahrenheit converter.
The °F to °C Formula
The conversion subtracts 32 (to account for the different zero points of the two scales) then scales by 5/9 (because one Fahrenheit degree is only 5/9 the size of a Celsius degree).
°C = (°F − 32) ÷ 1.8
Example: (98.6°F − 32) × 5/9 = 66.6 × 0.5556 = 37.0°C
For the reverse — Celsius back to Fahrenheit — multiply by 1.8 and add 32. Our °C to °F converter handles that direction.
Key Temperature Reference Points
These anchor points are worth memorising — they let you sanity-check any conversion instantly.
| °F | °C | What it is |
|---|---|---|
| −40°F | −40°C | Only point where °F and °C are equal |
| 0°F | −17.8°C | Fahrenheit zero (brine/salt-water freezing point) |
| 32°F | 0°C | Freezing point of water |
| 39°F | 3.9°C | Refrigerator safe zone |
| 50°F | 10°C | Cool autumn day |
| 59°F | 15°C | Mild spring temperature |
| 68°F | 20°C | Comfortable room temperature |
| 77°F | 25°C | Warm summer day |
| 86°F | 30°C | Hot weather |
| 95°F | 35°C | Very hot; heat advisory territory |
| 98.6°F | 37°C | Normal adult body temperature |
| 100.4°F | 38°C | Fever threshold (medical definition) |
| 104°F | 40°C | High fever — seek medical advice |
| 212°F | 100°C | Boiling point of water (sea level) |
US Weather Guide in Celsius
If you're visiting the US and more comfortable with Celsius, this chart maps US forecast temperatures to metric equivalents and explains what to expect.
| °F | °C | US Forecast Description | What to Wear |
|---|---|---|---|
| 0–10°F | −18 to −12°C | Extreme cold, wind chill warnings | Full cold-weather gear; face protection |
| 10–20°F | −12 to −7°C | Very cold; ice and snow likely | Heavy coat, hat, gloves essential |
| 20–32°F | −7 to 0°C | Below freezing; icy conditions | Heavy winter coat, layers |
| 32–40°F | 0 to 4°C | Just at or above freezing; frost possible | Heavy coat, scarf |
| 40–50°F | 4 to 10°C | Cold; typical US autumn/spring | Coat or heavy jacket |
| 50–60°F | 10 to 16°C | Cool; pleasant for outdoor activity | Light jacket or sweater |
| 60–70°F | 16 to 21°C | Mild; US "room temperature" outdoors | T-shirt and light layer |
| 70–80°F | 21 to 27°C | Warm; classic "nice day" | T-shirt; sunscreen advisable |
| 80–90°F | 27 to 32°C | Hot; summer typical for much of US | Light clothing; stay hydrated |
| 90–100°F | 32 to 38°C | Very hot; heat index warnings possible | Minimal clothing; limit sun exposure |
| 100°F+ | 38°C+ | Extreme heat; heat advisory / warning | Seek air conditioning; danger for elderly |
Oven Temperatures: °F to °C
US recipes specify oven temperatures in Fahrenheit; European, UK, and Australian recipes use Celsius. This chart includes the Gas Mark equivalent and fan/convection oven adjustment (fan ovens typically run 25°F / 15°C hotter than the stated temperature).
| °F (Conventional) | °C (Conventional) | °C Fan/Convection | Gas Mark | Description |
|---|---|---|---|---|
| 225°F | 107°C | 90°C | ¼ | Very slow / low |
| 250°F | 121°C | 105°C | ½ | Very slow |
| 275°F | 135°C | 115°C | 1 | Slow |
| 300°F | 149°C | 130°C | 2 | Slow |
| 325°F | 163°C | 145°C | 3 | Moderately slow |
| 350°F | 177°C | 160°C | 4 | Moderate |
| 375°F | 190°C | 170°C | 5 | Moderately hot |
| 400°F | 204°C | 185°C | 6 | Hot |
| 425°F | 218°C | 200°C | 7 | Very hot |
| 450°F | 232°C | 215°C | 8 | Very hot |
| 475°F | 246°C | 230°C | 9 | Extremely hot |
| 500°F | 260°C | 245°C | 10 | Max / pizza temperature |
Body Temperature & Fever Guide
The US measures body temperature in Fahrenheit; most of the rest of the world uses Celsius. Here's what each reading means:
| °F | °C | Medical Interpretation |
|---|---|---|
| Below 96.8°F | Below 36°C | Hypothermia (below normal); seek medical care |
| 96.8–97.9°F | 36–36.6°C | Below normal; may be normal for individual |
| 97.9–99°F | 36.6–37.2°C | Normal adult temperature range |
| 98.6°F | 37°C | Classic "normal" temperature average |
| 99–100.4°F | 37.2–38°C | Low-grade fever or elevated temperature |
| 100.4°F | 38°C | Fever threshold (CDC/medical definition) |
| 100.4–102°F | 38–38.9°C | Mild fever; rest and fluids advised |
| 102–104°F | 38.9–40°C | Moderate fever; consult a doctor |
| Above 104°F | Above 40°C | High fever; seek medical attention promptly |
| Above 107°F | Above 41.7°C | Hyperpyrexia; medical emergency |
Full Conversion Table: 0–500°F to °C
| °F | °C | °F | °C | °F | °C |
|---|---|---|---|---|---|
| 0 | −17.8 | 80 | 26.7 | 250 | 121.1 |
| 5 | −15.0 | 85 | 29.4 | 275 | 135.0 |
| 10 | −12.2 | 90 | 32.2 | 300 | 148.9 |
| 15 | −9.4 | 95 | 35.0 | 325 | 162.8 |
| 20 | −6.7 | 98.6 | 37.0 | 350 | 176.7 |
| 25 | −3.9 | 100 | 37.8 | 375 | 190.6 |
| 30 | −1.1 | 100.4 | 38.0 | 400 | 204.4 |
| 32 | 0.0 | 104 | 40.0 | 425 | 218.3 |
| 35 | 1.7 | 110 | 43.3 | 450 | 232.2 |
| 40 | 4.4 | 120 | 48.9 | 475 | 246.1 |
| 45 | 7.2 | 130 | 54.4 | 500 | 260.0 |
| 50 | 10.0 | 140 | 60.0 | — | — |
| 55 | 12.8 | 150 | 65.6 | — | — |
| 60 | 15.6 | 160 | 71.1 | — | — |
| 65 | 18.3 | 175 | 79.4 | — | — |
| 68 | 20.0 | 200 | 93.3 | — | — |
| 70 | 21.1 | 212 | 100.0 | — | — |
| 75 | 23.9 | 225 | 107.2 | — | — |
Frequently Asked Questions
What is 72°F in Celsius?
72°F equals 22.2°C. This is a very comfortable indoor temperature, close to the standard US office thermostat setting. Formula: (72 − 32) × 5/9 = 40 × 0.5556 = 22.2°C.
What is 98.6°F in Celsius?
98.6°F equals exactly 37°C. This is the classic figure for normal adult body temperature. It's worth knowing that in practice, healthy individuals vary between about 97°F (36.1°C) and 99°F (37.2°C) depending on the time of day and measurement method.
What is 350°F in Celsius?
350°F equals 176.7°C (often rounded to 175–180°C). This is one of the most common oven temperatures in US recipes — described as "moderate" and equivalent to Gas Mark 4. It's used for cakes, biscuits, cookies, and most everyday baking. In a fan/convection oven, reduce to about 160°C (320°F).
What is 400°F in Celsius?
400°F equals 204.4°C (often stated as 200°C in metric recipes). This is a hot oven — Gas Mark 6 — used for roasting vegetables, cooking pizza at moderate heat, and recipes that benefit from a crisp exterior. In a fan oven, use about 185°C (365°F).
Is 100°F a fever?
100°F (37.8°C) is a borderline or very low-grade elevated temperature. The CDC and most physicians define a fever as a body temperature at or above 100.4°F (38°C). At exactly 100°F you are just below the standard fever threshold, though you may feel unwell. If the reading persists or rises, consult a healthcare provider.
How do I quickly estimate °F to °C in my head?
The most common mental trick: subtract 30 then divide by 2. So 80°F → (80 − 30) ÷ 2 = 25°C (true: 26.7°C). It's a slight underestimate but close enough for weather interpretation. For a tighter estimate, use the exact formula: subtract 32, then multiply by 0.556.
Why does the US use Fahrenheit instead of Celsius?
The US adopted Fahrenheit in the colonial era via British influence, and never mandated a switch to Celsius despite the Metric Conversion Act of 1975 making metric voluntary. Today, Fahrenheit persists in everyday American life — weather, cooking, body temperature — while Celsius is used in US science, medicine, and manufacturing. The UK formally adopted Celsius in the 1960s–70s; the US did not follow.
Sources & References
- BIPM – SI Units – defines the kelvin and Celsius temperature scales
- CDC – Heat Stress – temperature thresholds for heat-related illness
- NHS – Fever in Adults – body temperature and fever guidance
- USDA – Safe Minimum Cooking Temperatures
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Author
Shakeel Muzaffar is the Founder and Editor-in-Chief of MultiCalculators.com, bringing over 15 years of experience in digital publishing, product strategy, and online tool development. He leads the platform's editorial vision, ensuring every calculator meets strict standards for accuracy, usability, and real-world value. Shakeel personally oversees content quality, formula verification workflows, and the platform's commitment to publishing tools that are genuinely useful for students, professionals, and everyday users worldwide.
