The exact formula
To convert Celsius to Fahrenheit, multiply by 9/5 (or 1.8) and add 32: °F = °C × 1.8 + 32. To go the other way, subtract 32 and divide by 1.8: °C = (°F − 32) ÷ 1.8. Our Celsius to Fahrenheit converter does both instantly.
The mental shortcut
For a fast estimate, double the Celsius temperature and add 30. 20°C becomes about 70°F (the exact answer is 68°F). The trick is very close for normal weather temperatures, but the error grows at extremes, so use the formula for cooking and medical readings.
Everyday reference points
Water freezes at 0°C (32°F) and boils at 100°C (212°F) at sea level. A comfortable room is 20–22°C (68–72°F). A hot summer day is 30°C (86°F), and 35°C is 95°F. Normal body temperature is about 37°C (98.6°F), and a fever generally starts around 38°C (100.4°F). At −40 the two scales are equal.
Oven temperatures
Common baking settings: 150°C ≈ 300°F, 160°C ≈ 325°F, 180°C ≈ 350°F, 200°C ≈ 400°F, 220°C ≈ 425°F and 230°C ≈ 450°F. Fan (convection) ovens are often set about 20°C (or 25°F) lower than conventional ovens for the same recipe.
Why two scales?
The Fahrenheit scale is still used for everyday temperatures in the United States and a few other places, while almost every other country uses Celsius. Scientists also use Kelvin, which starts at absolute zero: K = °C + 273.15.
Travel tip
When traveling, remember a few anchor points: 10°C is cool (50°F), 20°C is mild (68°F), 30°C is hot (86°F). That's enough to decide what to pack.
Weather in the news
Heat waves and cold snaps are often reported in both units. If a forecast says 40°C, that's 104°F, dangerous heat that requires hydration and shade; check our water intake guide for hot-weather advice.
Frequently asked questions
What is the formula for Celsius to Fahrenheit?
°F = °C × 1.8 + 32.
What is 180°C in Fahrenheit?
356°F, usually rounded to 350°F in recipes.
What temperature is a fever?
Generally 38°C (100.4°F) or higher.
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees.