Back to Blog
Temperature

How to Convert Celsius to Fahrenheit (Formula & Calculator)

Updated November 2025 5 min read

Need to convert Celsius (°C) to Fahrenheit (°F)? You're in the right place. Use our instant calculator below, or scroll down to learn the simple formula and mental math tricks.

Instant Celsius to Fahrenheit Converter
=
...

The Conversion Formula

The formula to convert Celsius to Fahrenheit is simple:

°F = (°C × 1.8) + 32

In plain English: Multiply the Celsius temperature by 1.8, then add 32.

Example Calculation

Let's convert 20°C to Fahrenheit:

  1. Multiply 20 by 1.8: 20 × 1.8 = 36
  2. Add 32: 36 + 32 = 68
  3. Result: 20°C = 68°F

Quick Mental Math Trick 🧠

Don't have a calculator? Use this rough estimate method:

Double it and add 30
(Example: 20°C × 2 = 40, + 30 = 70°F)

Note: This gives an approximate result (70°F vs actual 68°F), but it's close enough for weather!

Common Temperature Conversions

Celsius (°C)Fahrenheit (°F)Description
-40°C-40°FExtremely Cold
0°C32°FFreezing Point of Water
10°C50°FCool Day
20°C68°FRoom Temperature
30°C86°FHot Day
37°C98.6°FBody Temperature
100°C212°FBoiling Point of Water

Why are there two scales?

The Celsius scale (part of the Metric system) is used by almost every country in the world. It's based on water: 0° is freezing and 100° is boiling.

The Fahrenheit scale (part of the Imperial system) is primarily used in the United States, Bahamas, Cayman Islands, Liberia, Palau, the Federated States of Micronesia, and the Marshall Islands. It was created by Daniel Gabriel Fahrenheit in 1724.

Need more precision?

For scientific calculations or when you need more than 2 decimal places, check out our full Temperature Converter tool which supports Kelvin and Rankine as well.