Ramp Calculator
Calculate ramp length and slope angle from rise height and slope ratio.
About this calculator
Accessibility ramps have to meet a maximum slope requirement, most notably the 1:12 ratio widely referenced from ADA guidance, and translating that ratio plus a given rise height into an actual ramp length and footprint takes a bit of geometry that's easy to get wrong when sketching a layout by hand. This calculator multiplies your rise height by the slope ratio to find the horizontal run, then applies the Pythagorean theorem to rise and run to find the total sloped ramp length, the actual surface length of the ramp itself. Enter rise height and your target slope ratio, and get both the run (how much horizontal space the ramp needs) and the sloped length (how much ramp material to order) at once, instead of computing each separately. Because a gentler slope ratio (a larger second number, like 1:16 or 1:20) produces a longer, gentler ramp needing more space and material, check your specific accessibility code's requirements, which sometimes call for a gentler slope than the 1:12 maximum depending on ramp length and rise.
Worked example
2ft rise at a 1:12 slope
Result: Ramp length ≈ 24.08 ft
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