Use carefully
Stair and ramp dimensions are regulated in many places. This calculator helps with geometry, but it does not check building code compliance.
Example
With a 7-inch rise and 11-inch run, the angle is arctan(7 / 11), or about 32.5 degrees. The same relationship can also be expressed as about 63.6% slope.
Common mistakes
Do not use stair comfort rules for wheelchair ramps or accessibility ramps. Ramps often have much lower allowed slopes and different landing requirements.
Limitations
The same rise/run relationship can be expressed as degrees, percent slope or pitch per 12. For real construction, verify local code for stairs, ramps, landings, handrails and headroom.
Last reviewed: 2026-05-17