How to Convert Fahrenheit to Celsius

The Fahrenheit to Celsius Formula

Converting Fahrenheit to Celsius requires two operations: subtracting the offset and scaling the result. The Fahrenheit scale places the freezing point of water at 32°F and the boiling point at 212°F, giving a 180-degree range. The Celsius scale spans 0°C to 100°C for the same range. The formula is:

°C = (°F − 32) × 5/9

First subtract 32 to remove the Fahrenheit offset, then multiply by 5/9 (approximately 0.5556) to scale from the 180-degree Fahrenheit range to the 100-degree Celsius range.

Step-by-Step Examples

Example 1: Converting 72°F to Celsius

• Step 1: Subtract 32: 72 − 32 = 40.
• Step 2: Multiply by 5/9: 40 × 5/9 = 22.22.
• Result: 72°F equals 22.22°C (a comfortable room temperature).

Example 2: Converting 98.6°F to Celsius

• Step 1: Subtract 32: 98.6 − 32 = 66.6.
• Step 2: Multiply by 5/9: 66.6 × 5/9 = 37.
• Result: 98.6°F equals 37°C (normal body temperature).

Example 3: Converting 32°F to Celsius

• Step 1: Subtract 32: 32 − 32 = 0.
• Step 2: Multiply by 5/9: 0 × 5/9 = 0.
• Result: 32°F equals 0°C (the freezing point of water).

For instant results, use our temperature converter.

Quick Reference Table

Quick Mental Math Trick

For a fast approximation going from Fahrenheit to Celsius, use the subtract 30, then halve method. Take the Fahrenheit temperature, subtract 30, and divide by 2. For example, 80°F becomes (80 − 30) / 2 = 25°C. The actual answer is 26.67°C, so the estimate is reasonably close. This shortcut works best in the everyday temperature range of 30°F to 100°F.

Real-World Applications

Weather Forecasts

If you travel from the United States to a country using Celsius, understanding the conversion is essential for daily planning. When a forecast says 35°C, you need to know that is 95°F and you should dress for hot weather. A reading of 0°C means 32°F and icy conditions.

Cooking and Baking

American recipes typically give oven temperatures in Fahrenheit, while international recipes use Celsius. Converting 350°F to Celsius gives 176.67°C, commonly rounded to 180°C. A recipe at 425°F equals 218.33°C, rounded to 220°C.

Medical Settings

In the United States, body temperature is measured in Fahrenheit, with 98.6°F as the normal baseline. A fever of 101°F is 38.33°C, while 104°F is 40°C and requires immediate medical attention. Medical professionals who work with international patients need fluency in both scales.

Science and Engineering

Scientific research universally uses Celsius (and Kelvin). If you are reading a study that mentions a reaction occurring at 150°C, converting to 302°F provides an intuitive sense of the temperature involved.

Frequently Asked Questions

What is 72°F in Celsius?

72°F equals 22.22°C. This is a typical comfortable room temperature. Subtract 32 to get 40, then multiply by 5/9 to get 22.22°C.

What is the formula to convert Fahrenheit to Celsius?

The formula is: °C = (°F − 32) × 5/9. Subtract 32 from the Fahrenheit value, then multiply by 5/9 (approximately 0.5556).

At what temperature are Fahrenheit and Celsius the same?

The two scales intersect at −40 degrees. At this point, −40°F equals −40°C. It is the only temperature where both scales read the same value.

Quick Reference Section

Keep these formulas handy:

• Fahrenheit to Celsius: °C = (°F − 32) × 5/9
• Celsius to Fahrenheit: °F = (°C × 9/5) + 32
• Mental shortcut (F to C): Subtract 30, then halve
• Key anchor: 32°F = 0°C, 212°F = 100°C

For precise conversions, use our free temperature converter.