Ramp Slope Calculator
Estimate ramp length and angle with ADA slope check.
Estimate ramp length and angle with an ADA slope check. The calculator uses the rise and run to determine the ramp’s surface length and helps check whether the slope meets the ADA maximum of 1:12.
Ramp run
24
ft horizontal
Ramp length
24.1
ft (surface)
ADA ✓
8.3%
4.8°
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How does the ramp slope calculator work?
Ramp length (surface) = √(rise² + run²). ADA requires 1:12 maximum slope, with each ramp run limited to 30 ft (30 in of rise) before a landing.
What else do people ask about this calculator?
What is the ADA ramp slope?
Maximum 1:12 (8.33% or 4.76°). For 24 in of rise, that's a 24 ft ramp run plus landings.
How long a ramp for 3 steps?
3 steps ≈ 21 in rise → 21 ft of ramp run at ADA 1:12 slope, plus a 5 ft landing at top and bottom.
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