Roof Pitch and Rafter Calculator 🏠

Calculate roof pitch (slope), angle in degrees, and rafter length based on span and rise. Perfect for roofing projects, carpentry, and construction planning with customary and metric units.

🏠 Roof Pitch Components

Span = Building width | Rise = Vertical height | Run = Span ÷ 2 | Rafter = Diagonal length

Embed Roof Pitch and Rafter Calculator 🏠 Widget

About Roof Pitch and Rafter Calculator 🏠

Calculate Your Roof Pitch and Rafters

Enter your building span and roof rise to instantly calculate the roof pitch, angle in degrees, and rafter length. Perfect for roofers, carpenters, architects, and DIY builders planning residential or commercial roofing projects.

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Accurate Pitch Calculation

Calculate roof slope as ratio, percentage, and traditional x:12 format for precise planning.

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Rafter Length

Get exact rafter measurements using Pythagorean theorem for material estimation.

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Angle in Degrees

Know the exact roof angle for cutting rafters and planning roof structure.

How to Use the Roof Pitch Calculator

Select your measurement system (imperial or metric), enter the total building span (width) and the roof rise (vertical height from wall top to ridge). The calculator automatically computes the roof pitch, angle, and rafter length needed for your roofing project.

Understanding Roof Pitch

Roof pitch is the steepness of a roof expressed as a ratio of vertical rise to horizontal run. In the US, it's commonly expressed as "x:12" (how many inches the roof rises for every 12 inches of horizontal distance). For example, a 6:12 pitch means the roof rises 6 inches for every 12 inches of run.

Common Roof Pitch Applications

Low slope (2:12 to 4:12): Modern homes, prairie-style architecture, easier to work on but requires proper waterproofing
Medium slope (4:12 to 9:12): Most common for residential homes, good balance of drainage and walkability
Steep slope (9:12 and up): Traditional designs, excellent drainage, more material needed, challenging to work on
Flat (less than 2:12): Commercial buildings, requires special roofing materials and drainage systems

Typical Roof Pitch Reference

Pitch (x:12)	Angle (degrees)	Slope Type	Common Use
2:12	9.5°	Low	Porches, sheds
4:12	18.4°	Low-Medium	Garages, modern homes
6:12	26.6°	Medium	Residential standard
8:12	33.7°	Medium-Steep	Traditional homes
12:12	45.0°	Steep	A-frames, Gothic style