Rise Over Run Formula For Roofs

This page offers you the rise and run formula to find the pitch slope angle of the roof of a building.

Rise over run formula for roofs. Rafter rise run 1 5 6 2 25 36 38 25 rafter 38 25 6 18 m. Tan a rise y 1 run x our sketch above shows how we calculate the roof rise per horizontal foot 12 inches of run when we are given the roof slope in degrees or as the roof pitch or angle expressed in degrees the purple sloped line is the sloping roof surface. Rise run pitch use this when you express the pitch in percent pitch tan angle use this when you express the angle of the roof pitch in degrees what is the standard pitch of a roof. Calculate the rafter length substituting these values into the following formula.

Slope measures the angle of change in elevation which can be obtained by dividing rise by run and multiply the result with 100. The pitch value can be obtained by dividing n by 12 and divide s by the answer. Calculate the roof pitch as the proportion of rise and run. Typically in construction we express roof slopes as units of rise per single unit of run such as 3 inches of rise per 12 inches of run or 3 per ft.

To find slope divide rise by run and multiply it by 100 and for angle take tan 1 of s n. 3 in 12 or 3 12 slope as an angle. Let s say it is equal to 1 5 m. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares.

Here is an online rise and run calculator which helps to calculate pitch slope and angle with the help of rise and run values. For example if you measure 4 inches the pitch of your roof is 4 12. Slope as rise run e g. This will give you the rise over run or pitch.

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. The following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72. Pitch rise run 1 5 6 25. Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree.

Grade rise run 100 which equals 1 19 081 100 5 2408. Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run.