How to Calculate Degrees Celsius From Fahrenheit

The Celsius and Fahrenheit scales are two of the most commonly used temperature measurement systems. While Celsius is used in most countries, Fahrenheit is primarily used in the United States. Understanding how to convert between these two scales is essential for international travel, scientific research, and everyday life.

What is Celsius?

The Celsius scale, also known as the centigrade scale, is a temperature scale used by the International System of Units (SI). It is based on the freezing point of water at 0°C and the boiling point of water at 100°C at standard atmospheric pressure. The Celsius scale is widely used in scientific and everyday contexts worldwide.

Key points about the Celsius scale:

0°C is the freezing point of water
100°C is the boiling point of water
Each degree represents a 1°C change in temperature
Used in most countries except the United States

What is Fahrenheit?

The Fahrenheit scale is a temperature scale based on a system proposed by the Polish-German physicist Daniel Gabriel Fahrenheit. It uses the freezing point of water at 32°F and the boiling point of water at 212°F at standard atmospheric pressure. The Fahrenheit scale is primarily used in the United States and a few other countries.

Key points about the Fahrenheit scale:

32°F is the freezing point of water
212°F is the boiling point of water
Each degree represents a 1°F change in temperature
Used primarily in the United States

Conversion Formula

To convert a temperature from Fahrenheit to Celsius, you can use the following formula:

°C = (°F - 32) × 5/9

Where:

°C is the temperature in degrees Celsius
°F is the temperature in degrees Fahrenheit

This formula works because the Fahrenheit scale has a different zero point and a different size for each degree compared to the Celsius scale.

How to Convert Fahrenheit to Celsius

Converting Fahrenheit to Celsius is a straightforward process that can be done using the formula mentioned above. Here's a step-by-step guide:

Start with the temperature in Fahrenheit (°F)
Subtract 32 from the Fahrenheit temperature
Multiply the result by 5/9
The result is the temperature in Celsius (°C)

Example: Convert 68°F to Celsius

°C = (68 - 32) × 5/9 = 36 × 5/9 = 20°C

You can use our interactive calculator on the right to perform this conversion quickly and accurately.

Common Temperature Conversions

Here's a table showing common temperature conversions between Fahrenheit and Celsius:

Fahrenheit (°F)	Celsius (°C)	Description
32	0	Freezing point of water
68	20	Room temperature
98.6	37	Average human body temperature
212	100	Boiling point of water

FAQ

Why do some countries use Celsius and others use Fahrenheit?: Historical reasons play a significant role. The Celsius scale was developed based on the properties of water, while the Fahrenheit scale was developed based on a mixture of water, ice, and salt. The Celsius scale became more widely adopted in the 19th century due to its scientific basis.
Is there a simple way to estimate Fahrenheit to Celsius conversions?: Yes, you can use the approximation that 1°F is roughly 0.5556°C. For example, 10°F is approximately 5.5556°C. While this is not exact, it provides a quick estimate.
Why is the freezing point of water 0°C and 32°F?: The Celsius scale defines 0°C as the freezing point of water, while the Fahrenheit scale defines 32°F as the freezing point. This difference arises from the historical development of each scale.
Can I use this formula for very high or very low temperatures?: The formula works for all temperatures, but it's important to note that the relationship between Fahrenheit and Celsius is linear, meaning the difference between two temperatures in Fahrenheit is exactly 1.8 times the difference in Celsius.