Fahrenheit to Celsius - Formula, Table and Converter

How to convert Fahrenheit to Celsius

The formula is: °C = (°F - 32) x 5/9. Two steps: first subtract 32 from the Fahrenheit value, then multiply by 5/9 (or divide by 1.8). Example: convert 350°F. 350 minus 32 = 318. 318 times 5/9 = 176.67°C. Round to 177°C for your oven.

To convert the other direction (Celsius to Fahrenheit): °F = (°C x 9/5) + 32. Example: 200°C. 200 times 9/5 = 360. 360 plus 32 = 392°F. The calculator above handles both directions automatically.

Why do two temperature scales exist?

Daniel Gabriel Fahrenheit created his scale in 1714. He set 0°F as the temperature of an ice-salt-water mixture and 96°F as body temperature (slightly off by modern measurements). Anders Celsius developed his scale in 1742, using the freezing point of water (0°C) and boiling point (100°C) as anchors.

Today, the US, Myanmar and Liberia still use Fahrenheit for everyday purposes. Every other country uses Celsius. Scientists worldwide use Kelvin, but that is impractical for cooking. The result: anyone following American recipes outside the US needs to convert oven temperatures.

Oven temperatures: the essential cheat sheet

When an American recipe says "preheat to 350°F," set your Celsius oven to 175°C (or 160°C for fan/convection, since fan ovens run about 20°C hotter). Here are the key conversions: 325°F = 163°C, 350°F = 177°C, 375°F = 191°C, 400°F = 204°C, 425°F = 218°C.

Round to your oven's nearest setting. Most European ovens use 10°C increments: 150, 160, 170, 180, 190, 200, 220, 250. So 350°F (177°C) becomes 180°C on most ovens. 400°F (204°C) becomes 200°C. Close enough for excellent results.

Common mistake: a recipe says "Bake at 350" without specifying °F or °C. If it is an American recipe, it always means Fahrenheit. No home oven reaches 350°C - that would be 662°F, far beyond residential equipment.

Body temperature and health

Normal body temperature: 98.6°F = 37°C. Fever starts at 100.4°F = 38°C. High fever: 104°F = 40°C. If you read US health advice or use an American thermometer, these conversions help you assess the numbers quickly.

Note that 98.6°F was established in the 1800s. Modern studies suggest the average human body temperature has dropped slightly to about 97.9°F (36.6°C). But 98.6°F remains the commonly cited benchmark.

Weather temperature reference

For reading US weather forecasts: 32°F = 0°C (frost). 50°F = 10°C (cool jacket weather). 68°F = 20°C (comfortable room temperature). 86°F = 30°C (hot summer day). 104°F = 40°C (extreme heat wave). These five values let you estimate any Fahrenheit weather report.

Quick mental trick: subtract 30, then divide by 2. Example: 80°F. (80 - 30) / 2 = 25°C. The real answer is 26.7°C. Off by less than 2 degrees - good enough for deciding what to wear.

The point where Fahrenheit equals Celsius

There is exactly one temperature where both scales show the same number: -40 degrees. -40°F = -40°C. This is a fun trivia fact, but it also has practical value. It proves that the scales are linear and will cross exactly once. Above -40, Fahrenheit numbers are always higher. Below -40 (extremely rare), Fahrenheit numbers are lower.