Where Fahrenheit-to-Celsius matters
Three situations cover almost every search: following a US recipe on a metric oven, reading a weather forecast in the wrong units, and checking a thermometer built for the US market. Each has its own tolerance for error, so decide which you have before choosing a shortcut.
- • Use °F For: US recipes and cookbooks (oven dials in °F), US weather forecasts and apps, US clinical thermometers and fever guides, US thermostats and HVAC displays
- • Use °C For: UK, EU and other metric oven dials, Metric weather reports worldwide, Metric medical devices and hospital charts, Scientific work and lab equipment
Rule of Thumb: Cooking: 325°F = 163°C, 350°F = 177°C (round to 180°C), 375°F = 191°C, 400°F = 204°C. Weather: 32°F is freezing, 50°F is 10°C, 68°F is 20°C and 86°F is 30°C.
Fahrenheit to Celsius Conversion Formula — How to Convert °F to °C
°C = (°F − 32) × 5/9
Quick mental estimate: subtract 32, halve it, then add a tenth of the half. For 68°F, 36 ÷ 2 = 18, plus 1.8 gives about 19.8°C (exact: 20).
Step-by-Step °F to °C Conversion Examples:
- •A 350°F oven:(350 − 32) × 5/9 =176.7°C (most UK and EU recipes round this to 180°C)
- •Normal body temperature:(98.6 − 32) × 5/9 =37°C
- •A 72°F room:(72 − 32) × 5/9 =22.2°C
- •A 98°F reading:(98 − 32) × 5/9 =36.7°C
Why the Fahrenheit to Celsius Conversion Works & Common °F to °C Converter Mistakes to Avoid
The scales start counting from different places. Fahrenheit puts the freezing point of water at 32 and Celsius at 0, so subtracting 32 lines them up. After that, Fahrenheit spreads the freezing-to-boiling range over 180 degrees where Celsius uses 100, which is why the result is multiplied by 5/9 (the same as dividing by 1.8).
The Common °F to °C Converter Mistake: Multiplying before subtracting. The 32 has to come off first: (68 − 32) × 5/9 = 20°C, whereas 68 × 5/9 − 32 gives a nonsense answer. The quick estimate also fails for health readings: it takes 100.4°F to about 35°C, when the real figure is 38°C. Use the full formula for anything medical.
Fahrenheit to Celsius Real-World Size Comparison Table
These are the readings people look up most often: the oven settings in American recipes, body temperature thresholds, and numbers from a US weather forecast.
| Fahrenheit (°F) | Celsius (°C) | Real-World Size Benchmark |
|---|---|---|
| -40 °F | -40 °C | The point where both scales read the same |
| 0 °F | -17.78 °C | About the temperature of a home freezer |
| 32 °F | 0 °C | Water freezes |
| 50 °F | 10 °C | A cool spring day |
| 68 °F | 20 °C | A comfortable room temperature |
| 86 °F | 30 °C | A hot summer day |
| 98.6 °F | 37 °C | Average adult body temperature |
| 100.4 °F | 38 °C | The usual threshold for a fever |
| 212 °F | 100 °C | Water boils at sea level |
| 325 °F | 162.78 °C | A low baking oven |
| 350 °F | 176.67 °C | A standard baking temperature |
| 375 °F | 190.56 °C | A common setting for cookies and casseroles |
| 400 °F | 204.44 °C | A hot oven for roasting vegetables |
| 450 °F | 232.22 °C | A very hot oven, used for pizza and searing |
°F to °C Converter in Spreadsheets — Spreadsheet Shortcut (Excel & Google Sheets)
With Fahrenheit in cell A1, =(A1-32)*5/9 returns Celsius and =A1*9/5+32 does the reverse. The built-in =CONVERT(A1,"F","C") gives the same result in one step. Paste a column of oven settings or weather readings and drag the formula down.
Fahrenheit to Celsius Conversion — Frequently Asked Questions
How do I convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9 (or divide by 1.8). For example, 77°F − 32 = 45, and 45 × 5/9 = 25°C.
What is 350°F in Celsius?
350°F is 176.7°C. Most UK and EU recipes round it to 180°C. For a fan oven, a recipe usually drops about 20°C from that figure.
What is 98.6°F in Celsius?
Exactly 37°C, the traditional average adult body temperature.
Is 100.4°F a fever?
100.4°F equals 38°C, the usual threshold for a fever. This page converts numbers and is not medical advice.
What is 100°F in Celsius?
100°F is 37.8°C, a very hot day or a slightly raised body temperature.
What is 0°F in Celsius?
0°F is about −17.8°C, roughly the temperature of a home freezer.
Are Celsius and centigrade the same?
Yes. Celsius is the modern name for the scale that used to be called centigrade.
At what temperature are Fahrenheit and Celsius equal?
At −40. Both scales read −40 there, which makes it a handy sanity check for any converter.
°F to °C Quick-Reference Conversion Table
The conversions people look up most often for cooking, weather and thermometers, plus the reverse and Kelvin formulas.
| To convert | Operation | Example |
|---|---|---|
| °F → °C | (− 32) × 5/9 | 212°F → 100°C |
| °C → °F | (× 9/5) + 32 | 100°C → 212°F |
| °F → K | (− 32) × 5/9 + 273.15 | 32°F → 273.15 K |
| K → °F | (− 273.15) × 9/5 + 32 | 373.15 K → 212°F |