Fahrenheit Degré Calcul

Convert temperatures between Fahrenheit and Celsius with our precise online calculator. Learn the conversion formula, see practical examples, and understand the differences between these two temperature scales.

Conversion Formula

The relationship between Fahrenheit (°F) and Celsius (°C) is defined by these formulas:

Fahrenheit to Celsius

°C = (°F - 32) × 5/9

Celsius to Fahrenheit

°F = (°C × 9/5) + 32

These formulas are derived from the linear relationship between the two scales. The key points are:

0°C is equal to 32°F
100°C is equal to 212°F
The difference between the two scales is 1.8 times the Celsius value

Important Notes

The formulas work for all temperatures, but extreme values may require special handling in scientific applications. The conversion is linear and consistent across the entire range of measurable temperatures.

How to Use This Calculator

Our Fahrenheit to Celsius calculator is simple to use:

Enter the temperature value in the input field
Select the source unit (Fahrenheit or Celsius)
Click the "Calculate" button
View the converted temperature in the result box
Use the "Reset" button to clear the form

For example, to convert 98.6°F (normal human body temperature) to Celsius:

Enter 98.6 in the input field
Select Fahrenheit from the dropdown
Click Calculate
The result will show 37°C

The calculator handles both directions of conversion automatically based on your selection.

Common Temperature Conversions

Here are some common temperature conversions you might need:

Fahrenheit	Celsius	Description
32°F	0°C	Freezing point of water
212°F	100°C	Boiling point of water
98.6°F	37°C	Average human body temperature
-40°F	-40°C	Equal point on both scales
-4°F	-20°C	Average winter temperature in many regions

This table provides quick reference points for common temperatures in both scales.

Understanding Temperature Scales

Fahrenheit Scale

The Fahrenheit scale is commonly used in the United States and a few other countries. It was developed by Daniel Gabriel Fahrenheit in the early 18th century. Key characteristics:

Based on a mixture of water, ice, and salt
0°F is the freezing point of a brine solution
96°F is the average human body temperature
180°F is the boiling point of water

Celsius Scale

The Celsius scale is part of the metric system and is used worldwide. It was developed by Anders Celsius in the mid-18th century. Key characteristics:

Based on the freezing and boiling points of water
0°C is the freezing point of water
100°C is the boiling point of water
More intuitive for scientific use

The difference between the two scales is that the Celsius scale has a smaller degree size (1°C = 1.8°F), making it more precise for scientific measurements.

Frequently Asked Questions

How do I convert Fahrenheit to Celsius?

Use the formula °C = (°F - 32) × 5/9. For example, 68°F converts to 20°C.

What is the difference between Fahrenheit and Celsius?

The main difference is the size of the degree. 1°C is equal to 1.8°F, so the Celsius scale has smaller increments. The freezing point of water is 0°C (32°F) and the boiling point is 100°C (212°F).

Why do we need both scales?

Fahrenheit is used in the US and a few other countries, while Celsius is part of the metric system used worldwide. The choice depends on regional standards and specific applications.

What is the coldest temperature possible?

Absolute zero is -273.15°C (-459.67°F), the point at which molecular motion stops. In practice, temperatures can't reach absolute zero.

How accurate is this calculator?

This calculator uses precise mathematical formulas and provides results accurate to multiple decimal places. For most practical purposes, the results are exact.