Fahrenheit to Celsius

How Fahrenheit ↔ Celsius conversion works

Temperature scales are linear but offset: freezing and boiling of water sit at different numbers on °F and °C. Converting is not a simple multiply by a constant without an offset — you must subtract or add 32 at the right step. That is the most common source of mental-math errors when traveling or following a recipe from another country.

Formulas

°C = (°F − 32) × 5/9. °F = °C × 9/5 + 32. Reference points at standard pressure: water freezes at 32°F = 0°C and boils at 212°F = 100°C. Room comfort often sits near 68–72°F (20–22°C).

Worked examples

• 68°F (a common indoor setting) = 20°C.
• 37°C (approximate human body temperature) = 98.6°F.
• −40° is the same on both scales — a useful memory check.
• 350°F oven ≈ 176.7°C; 180°C oven ≈ 356°F.

Weather and cooking reference

• 0°C = 32°F (freezing)
• 10°C = 50°F (cool)
• 25°C = 77°F (warm)
• 30°C = 86°F (hot for many climates)
• 100°C = 212°F (boiling)

Everyday uses

Weather apps, oven recipes, fever checks, and travel packing lists often mix scales depending on the country. Convert the number before adjusting a thermostat or baking temperature so you do not confuse a moderate day with a heatwave, or bake at a dangerously wrong setting.

How to use it

1. Enter a temperature in °F or °C.
2. Read the linked field for the other scale.
3. For cooking, double-check whether the recipe author’s country uses Fahrenheit ovens.

Common mistakes

• Multiplying by 5/9 without subtracting 32 first (or the reverse when going to °F).
• Assuming “feels like” / wind chill equals air temperature — those indexes are different.
• Confusing oven gas marks with °C/°F without a chart for your oven model.

Frequently asked questions

Quick estimate without a calculator?

A rough °C≈ (°F − 30) / 2 trick is only for ballpark weather chat — use the exact formula for cooking or medicine.

What about kelvin?

Kelvin = °C + 273.15. This page does not convert to kelvin; add 273.15 after you have Celsius if you need SI absolute temperature.

Why do fever apps show 98.6°F and 37°C?

37°C converts to 98.6°F with the standard formula. Individual normal body temperature varies; follow clinical guidance rather than a single classic number.

Limitations

Does not convert to kelvin. Weather “feels like” indexes are not the same as air temperature. See also the metric and imperial conversions guide.