Slope Chart

Slope Factor Chart

When outfitting your residential or commercial structure with roofing materials from Bohon Roofing, it’s important to know the incline, or pitch, of your roof. Pitch is expressed as a ratio of the vertical rise to the horizontal span. In order to know what type of materials will work best for your project and the amount of materials required, you’ll need to find out the pitch of your roof.

Measuring Roof Pitch

To obtain an accurate roof pitch measurement, properly measure the rise and run. Using a tape measure, make a pencil mark 12 inches from the end of a carpenter’s level. Then, you’ll be able to measure slope from an unfinished attic space under the roof. Simply locate a roof rafter board, place the end of the level against the bottom edge and measure from the 12-inch mark vertically to the bottom edge of the rafter. This will give you the rise over run, or pitch. For example, if you measure 4 inches, the pitch of your roof is 4:12.

Pitch of Roof
Slope Factor
Valley and Hip Factor
1:12
1.0035
1.4167
2:12
1.0138
1.4240
3:12
1.01308
1.4362
4:12
1.0541
1.4530
5:12
1.0833
1.4743
6:12
1.1180
1.5000
7:12
1.1577
1.5298
8:12
1.2019
1.5635
9:12
1.2500
1.6008
10:12
1.3017
1.6415
11:12
1.3566
1.6853
12:12
1.4142
1.7320

Finding The Slope and Hip and Valley Factor

Once you’ve figured out the pitch of your roof, you can consult the following chart to discover the slope factor and hip and valley factor.

For the PDF Version of this chart, please click here.

For product recommendations based on the slope of your roof, contact a Bohon Roofing sales representative today. We’ll be happy to discuss your options, as well as answer any questions you may have regarding our roofing products.