HOW TO MEASURE A ROOF:

When measuring a roof from the ground three measurement are needed: The length of the roof (c) at the eaves, the span (b) of the roof at the eaves and the rise (a). The rise can usually be measured visually by multiplying the exposure of each siding panel times the number of planks as shown above.

Step by Step Procedures:

1. First, before you can use the roof calculator you need to make an outline of the roof on paper.
2. In order to use the Roof Calculator 6.1 you need to walk around the house and fill in your outline with your measurements making sure to account for overhang.
3. Section off the roof and write your calculations
4. Hips and Ridge: Visually count how many ridge tabs are on your roof. Multiply the tabs by inches based on its exposure, then divide by feet (12”). Exposure: composition shingles are usually 5.5", cedar shake 5.0", tile 10.5"-14".  (Measure a couple shingles to be sure the sizes are accurate.)
5. Enter your measurements into the roof calculator program and you will receive instant totals for squares of shingles, plywood, valley flashing, hip and ridge, felt, ice and water shield and more...