What is a standard pitch?

A 4/12 pitch is common for many residential homes, offering a good balance of drainage and walkability for maintenance.

Roof Pitch Calculator – Slope & Angle Service | CalcTools

Determine roof pitch over 12 and exact slope angle. Professional service for roofing and drainage.

The pitch of a roof determines its drainage, its structural requirements, and the materials needed for its construction. Understanding this vertical rise over horizontal run is essential for building rafters and ensuring weather resistance. Our Roof Pitch service provides the standard US 'pitch-over-12' ratio alongside the exact degree angle, ensuring that homeowners and roofers can communicate with mathematical clarity.

Vertical Rise

Horizontal Run

Standard Pitch

4/12

Roof angle: 18.4° (33.3% grade)

Vertical Rise4

Horizontal Run12

Slope Angle18.4°

How it Works

The tool uses basic trigonometry (Rise/Run) to calculate the slope. It normalizes this to a base-12 ratio for standard construction terms and uses inverse tangent functions to derive the precise angle in degrees.

Calculation Formula

Pitch = (Rise/Run) × 12 | Angle = arctan(Rise/Run)

Calculation Examples

1. **Common**: 6in rise, 12in run = **6/12 pitch (26.6°)**.

Why use this tool in your daily life?

Professional structural planning. This service ensures your roof meets local building codes for snow and wind loads, providing the foundational angles needed for safe and durable construction.