Temperature Conversion

Celsius to Fahrenheit: Formula and Quick Reference Chart

5 min read · Updated May 2025

Celsius and Fahrenheit are the two most widely used temperature scales in daily life. If you've ever looked at a weather forecast in another country and had no idea whether to wear a coat or shorts, this guide is for you.

Quick answer: To convert Celsius to Fahrenheit, multiply by 9/5 (or 1.8) and add 32. To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9 (or 0.5556).

The Formula

°F = (°C × 9/5) + 32
°C = (°F − 32) × 5/9

For a quick mental approximation, double the Celsius temperature and add 30. This gives a rough Fahrenheit equivalent that's close enough for everyday use. For example, 20°C → (20 × 2) + 30 = 70°F (exact answer: 68°F).

Key Reference Temperatures

Celsius (°C)Fahrenheit (°F)Description
-40°C-40°FThe point where both scales are equal
0°C32°FFreezing point of water
10°C50°FCold day
20°C68°FRoom temperature
25°C77°FWarm day
37°C98.6°FNormal body temperature
40°C104°FVery hot day / fever
100°C212°FBoiling point of water

Which Countries Use Celsius vs Fahrenheit?

The vast majority of the world — including all of Europe, Asia, Africa, South America, and Australia — uses Celsius as the standard temperature scale. The United States is the most notable exception, using Fahrenheit for everyday weather and cooking.

The Bahamas, Belize, and the Cayman Islands also use Fahrenheit for weather, though Celsius is used in scientific and medical contexts worldwide regardless of location.

Cooking Temperature Reference

Oven SettingCelsius (°C)Fahrenheit (°F)
Very Low120°C250°F
Low150°C300°F
Moderate180°C350°F
Hot200°C400°F
Very Hot220°C425°F

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