Calculer Une Pente De Toit En Degré

Calculating the pitch angle of a roof in degrees is essential for construction, roofing, and architectural planning. This calculator helps you determine the angle of a roof based on its rise and run measurements.

How to Calculate Roof Pitch Angle

The pitch angle of a roof is calculated using the rise and run measurements. The rise is the vertical distance from the eave to the ridge, while the run is the horizontal distance between two adjacent rafters.

For example, a roof with a 4/12 pitch means there is 4 units of rise for every 12 units of run.

Steps to Calculate

Measure the rise (vertical distance) of the roof.
Measure the run (horizontal distance) of the roof.
Use the formula to calculate the pitch angle in degrees.
Interpret the result to understand the roof's steepness.

The Formula

The pitch angle (θ) of a roof can be calculated using the arctangent function:

θ = arctan(rise / run) × (180 / π)

Where:

θ is the pitch angle in degrees
rise is the vertical distance from the eave to the ridge
run is the horizontal distance between two adjacent rafters
π is approximately 3.14159

The result will be the angle in degrees that represents the roof's pitch.

Worked Examples

Example 1: 4/12 Pitch

For a roof with a rise of 4 feet and a run of 12 feet:

θ = arctan(4 / 12) × (180 / π) ≈ 18.43°

This is a common pitch angle for residential roofs.

Example 2: 6/12 Pitch

For a roof with a rise of 6 feet and a run of 12 feet:

θ = arctan(6 / 12) × (180 / π) ≈ 26.57°

This pitch is steeper and commonly used for commercial buildings.

Common Roof Pitch Angles

Here are some common roof pitch angles and their typical uses:

Pitch (rise/run)	Angle (degrees)	Typical Use
1/12	4.76°	Flat roofs, green roofs
2/12	9.46°	Low-slope residential roofs
4/12	18.43°	Common residential roofs
6/12	26.57°	Commercial and industrial roofs
8/12	33.69°	Steep roofs, barns, sheds

Frequently Asked Questions

What is a roof pitch angle?

A roof pitch angle is the steepness of a roof measured in degrees. It's calculated from the rise and run measurements of the roof.

How do I measure the rise and run of a roof?

The rise is the vertical distance from the eave to the ridge, while the run is the horizontal distance between two adjacent rafters. Use a measuring tape to get these measurements.

What is a common residential roof pitch?

A common residential roof pitch is 4/12, which translates to approximately 18.43 degrees.

Can I use this calculator for any unit of measurement?

Yes, you can use any unit of measurement (feet, meters, inches, etc.) as long as you're consistent with the rise and run measurements.