Ramp Slope (ADA)
Slope ratio, percent, and pass/fail against 1:12 maximum.
Example
You enter
- Rise (in) 6
- Run (in) 72
You get
- Slope % 8.33 %
- Pass 1:12 pass
Checked against published worked examples from: U.S. Access Board.
Details, formula, and sources
Formula or tableSlope ratio (run:rise); 1:12 max per ADA Standards §405.2 (≤ 8.33% / 4.76°). Cross-slope ≤ 1:48 per ADA §403.3.
Source and editionADA Standards for Accessible Design (2010) §405; ICC A117.1-2017 by name.
Free accessADA Standards free at ada.gov; ICC A117.1 read-only at codes.iccsafe.org.
What governsEstimate. AHJ and licensed structural engineer govern.
API field namesrise_in, run_in, percent, pass_1_to_12
- Pass-fail threshold 1:12 (8.33%) maximum running slope; 1:48 max cross-slopeADA §405.2 / §403.3