Ridge Height Calculator (rise above the wall plate)
How high does the peak stand? Enter the horizontal run and the pitch to get the ridge rise above the wall plate, and add a plate height for the total height above the plate line.
Calculator
At 6/12 over a 14.0 ft run the ridge sits 7.00 ft above the wall plate.
The ridge is the peak where the two slopes of a gable roof meet. How far it rises above the top of the wall depends on just two things: the horizontal run and the pitch. Because pitch is rise per 12 of run, the ridge rise is simply the run multiplied by the pitch fraction — no trigonometry needed.
Enter the run (the horizontal distance from the wall to the ridge, which is half the span on a symmetric gable) and the pitch. The tool returns the ridge rise above the wall plate. If you also enter the wall-plate height above the floor or foundation, it adds the two to give the total ridge height above that reference line — useful for checking clearances, matching an addition to an existing roof, or estimating gable-end wall area.
Formula
- Ridge rise:
rise = run × (pitch ÷ 12) - Total height:
total = rise + plate_height
The pitch fraction (pitch ÷ 12) is the rise per unit of run; multiplying by the run scales it up to the full ridge rise.
Worked example
A 14 ft run at a 6/12 pitch:
- Rise:
14 × (6 ÷ 12) = 14 × 0.5 = 7.0 ft
The ridge stands 7.0 ft above the wall plate. If the plate itself is 9 ft above the floor, the ridge is 7.0 + 9 = 16.0 ft above the floor line. At a steeper 12/12 the same run gives a 14 ft rise.
Run vs. span & what the total covers
Run, not span. Use the run for one slope — wall to ridge — which on a symmetric gable is half the total building span. Entering the full span would double the rise. If the roof is asymmetric, each slope has its own run but they share the same ridge rise only when their pitches produce the same rise; otherwise the ridge is offset.
What the total height includes. The plate-height option is a convenience for adding the ridge rise on top of however high the top plate sits above your chosen reference (floor, ceiling or grade). It does not add the ridge board thickness or roofing build-up, which are small relative to the overall height and vary by construction.
Gable-end area. The ridge rise is also the height of the triangular gable above the plate. Its area is ½ × span × rise — handy when you take off siding for the gable ends. Pair this tool with the rafter length calculator to complete the frame geometry.