Fahrenheit to Celsius Converter — Convert °F to °C (Exact: °C = (°F − 32) × 5/9)
Accurate Fahrenheit (°F) to Celsius (°C) converter using the exact formula °C = (°F − 32) × 5/9. Built for cooking, weather, HVAC, healthcare, science labs, and travel.
Exact identity: °C = (°F − 32) × 5/9. Explore more in our temperature conversion tools category.
About Fahrenheit to Celsius Conversion
Fahrenheit (°F) still appears widely in the United States—on weather broadcasts, oven dials, thermostats, and medical thermometers. Celsius (°C) is standard across science, healthcare, and most of the world’s daily life. Converting °F → °C keeps notes, recipes, and readings aligned across borders without sacrificing accuracy.
Fahrenheit to Celsius Formula
Exact relationship
Use the scale-alignment equation:
°C = (°F − 32) × 5/9Examples:
68 °F → (68 − 32) × 5/9 = 20 °C
350 °F → (350 − 32) × 5/9 ≈ 176.67 °CRelated Temperature Converters
What is Fahrenheit?
Fahrenheit sets water’s freezing point at 32 °F and boiling at 212 °F (standard pressure), creating a 180-degree interval between them. Many people find its granularity intuitive for everyday weather ranges.
What is Celsius?
The Celsius scale anchors to 0 °C at water’s freezing point and 100 °C at boiling under standard pressure. It’s the modern, SI-aligned metric scale used in labs, hospitals, and international reporting.
Step-by-Step: Converting °F to °C
- Subtract 32 from the Fahrenheit value.
- Multiply by 5/9 (≈ 0.5556).
- Round to your needed precision and label the result in °C.
Walkthroughs for common scenarios:
Home oven: 375 °F → (375 − 32) × 5/9 ≈ 190.56 °C
Outdoor weather: 41 °F → (41 − 32) × 5/9 = 5 °C
Fever reading: 101.3 °F → (101.3 − 32) × 5/9 ≈ 38.5 °CEveryday Conversations (Natural Use Cases)
Cooking & baking
“The recipe says 425 °F—what is that in Celsius?” Answer: (425 − 32) × 5/9 ≈ 218.33 °C. Converting recipes keeps crust, crumb, and caramelization on target when your oven displays °C.
Weather & travel
“It’s going to be 77 °F in Florida—warm, right?” Answer: (77 − 32) × 5/9 = 25 °C. Conversions help travelers compare climates quickly.
Healthcare & fitness
“Thermometer shows 100.4 °F—should I be concerned?” Answer: (100.4 − 32) × 5/9 ≈ 38 °C, which is a mild fever. Always follow medical guidance for interpretation.
HVAC & building ops
“The service log is in °F but our BMS uses °C—how do we align?” Answer: Convert the setpoint block once and document the conversion so field notes, trend logs, and commissioning reports match.
Common Conversions
Everyday checks for kitchens, clinics, and weather desks
| °F | °C |
|---|---|
| 32 | 0 |
| 41 | 5 |
| 68 | 20 |
| 77 | 25 |
| 86 | 30 |
| 98.6 | 37 |
| 212 | 100 |
Quick Reference Table
| °C | °F |
|---|---|
| 0 | 32 |
| 20 | 68 |
| 25 | 77 |
| 30 | 86 |
| 37 | 98.6 |
| 50 | 122 |
| 100 | 212 |
Frequently Asked Questions
What is the exact formula for converting Fahrenheit to Celsius?
Use °C = (°F − 32) × 5/9. The −32 aligns the zero points (32 °F = 0 °C) and 5/9 rescales the 180 °F interval to 100 °C.
How do I convert Celsius back to Fahrenheit?
Use °F = (°C × 9/5) + 32. Both equations are exact; round only when displaying values for readability.
Why do ovens and recipes vary between °F and °C?
U.S. appliances and cookbooks typically use °F, while most other countries use °C. Converting keeps bake times and browning profiles consistent across kitchens.
Is 98.6 °F really 37 °C?
Yes. (98.6 − 32) × 5/9 = 37 °C. Body temperature varies slightly by person, time of day, and measurement method.
What precision should I show?
Weather and household readings are usually whole degrees. Healthcare often uses one decimal place, while lab instruments may require two or more decimals.
Are there quick mental approximations?
A handy rule is °C ≈ (°F − 30) ÷ 2. It’s rough but good for quick estimates; use this tool for exact values.
Do I treat negative temperatures differently?
No. The same formula works across the entire range. Just remember to subtract 32 before multiplying by 5/9.
What’s the boiling point of water in °F and °C?
At standard pressure, water boils at 212 °F (100 °C) and freezes at 32 °F (0 °C).
Why does the conversion subtract 32 first?
Because the zero points differ: 0 °C corresponds to 32 °F. Subtracting 32 aligns the baselines before scaling.
Where is Fahrenheit still common?
In the United States and certain U.S. territories. You’ll see it in weather reports, ovens, thermostats, and consumer thermometers.
Tips for Working with °F & °C
- Record the original scale and instrument resolution in notes; convert only for presentation layers.
- For ovens, check your manual—some models round to standard steps (e.g., 5 °C or 25 °F increments).
- When communicating to mixed audiences, include both units to reduce back-and-forth clarifications.
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