Skip to content

Roof Pitch Calculator

Enter Roof Pitch

Input method

Roof pitch input

RISE
RUN
Standard roof pitch is usually read as rise per 12 inches of run.

Field pitch reference

About this Roof Pitch Calculator

This roof pitch calculator converts rise and run, roof angle, or a known pitch into the values used for roof area planning. It returns roof pitch, angle, slope percent, and the pitch multiplier needed to estimate sloped roof surface from a flat footprint. These values feed directly into the Roof Area Calculator for planning roof surface area estimates.

How roof pitch is measured

Roof pitch is commonly measured as rise over 12 inches of horizontal run. For example, a 6/12 pitch rises 6 inches for every 12 inches of run. Pitch is used in roofing because it directly relates to framing and material coverage. If you have a roof angle from an inclinometer or drawing, this calculator can convert that angle back into pitch.

What the pitch multiplier does

The pitch multiplier adjusts a flat footprint area into estimated sloped roof surface area. A steeper pitch increases the multiplier because the sloped roof plane is longer than the horizontal run below it. This value is commonly used to convert footprint measurements into roof surface area and is important when estimating roofing squares.

Common roof pitch reference

Pitch Angle Multiplier
3/1214.0°1.031
4/1218.4°1.054
5/1222.6°1.083
6/1226.6°1.118
7/1230.3°1.158
8/1233.7°1.202
9/1236.9°1.250
10/1239.8°1.302
12/1245.0°1.414

Roof Pitch Calculator FAQ

What is roof pitch?

Roof pitch describes how much a roof rises over a horizontal run, commonly written as rise over 12 inches of run, such as 6/12.

What is a pitch multiplier?

A pitch multiplier converts a flat footprint measurement into sloped roof surface area. Steeper roofs have larger pitch multipliers.

What is the difference between roof pitch and slope percent?

Roof pitch is written as rise over run, such as 6/12. Slope percent expresses the same rise-run relationship as a percentage.

Can I enter a roof angle instead of rise and run?

Yes. Enter the roof angle in degrees and the calculator will convert it into roof pitch, slope percent, and pitch multiplier.