Roof Pitch Calculator

Calculate your roof pitch by entering the rise and run measurements. This calculator converts between pitch ratio (X/12), degrees, and percentage slope. Knowing your roof pitch is essential for ordering materials, planning drainage, and meeting building codes.

Enter Your Measurements

Rise(in)

Run(in)

Results

Pitch

6.00

/12

Angle

26.6

degrees

Slope

50.0

Pitch Multiplier

1.1180

Rafter Length per 12" Run

13.42

Formula

Pitch = (Rise ÷ Run) × 12 | Degrees = arctan(Rise ÷ Run) × 180 ÷ π | Multiplier = √(1 + (Rise ÷ Run)²)

How to Use This Calculator

How to Use

1
Measure the vertical rise in inches over a measured horizontal run.
2
Enter the rise and run values. For standard pitch notation, use a run of 12 inches.
3
The calculator shows the pitch ratio, angle in degrees, and the slope percentage.

Frequently Asked Questions

What is a common roof pitch?

The most common residential roof pitches are 4/12 to 8/12. A 6/12 pitch (26.6 degrees) is very common and provides a good balance of aesthetics and drainage.

What is the minimum roof pitch for shingles?

Asphalt shingles require a minimum pitch of 2/12 (9.5 degrees). Lower slopes need modified bitumen or membrane roofing systems.

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About This Calculator

This calculator uses the formula: Pitch = (Rise ÷ Run) × 12 | Degrees = arctan(Rise ÷ Run) × 180 ÷ π | Multiplier = √(1 + (Rise ÷ Run)²). All calculations follow industry-standard methods. Results are estimates — always verify with a licensed professional for structural or code-compliant work.

Built and maintained by the CalcSmart team. Last updated March 2026.

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