Calculate the height of a gable (rake) wall based on roof slope and half of the wall's horizontal length the "rake run".

Example calculation:

convert plate length amount of 12' - 6" into inches
12 * 12 + 6 = 150 inches

roof slope; divide the rise by the run
5 ÷ 12 = 0.4166667

multiply the length of the plate by this amount
150 * 0.4166667 = 62.5

The 62.5 inches is the increase in height for the rake wall from its lowest to the highest point.

If your wall has a starting height of 96" (8 feet) the rake wall will have a total height of 96 + 62.5 = 158.5 inches = 13' - 2 1/2"

Calculation

1. roof slope ratio of inches per foot
2. length of bottom plate in feet and inches (rake run)
3. lower wall height

Results

1. peak height in decimal inches
2. peak height in inches
3. peak height in feet and inches