Code and standard reference
ADA Ramp Slope
Last reviewed · BuildMath editorial team
The 2010 ADA Standards generally limit a ramp run to a 1:12 slope, 30 inches of rise per run, and 36 inches of clear width, with level landings at the top and bottom. Existing-site exceptions and detailed handrail, edge, surface, and maneuvering rules can apply. Verify the complete official standard and project scope.
Limit table
| Item | Limit or rule | Reference | Verification note |
|---|---|---|---|
| Running slope | Maximum 1:12 | 405.2 | Exceptions can apply to existing sites. |
| Rise per run | Maximum 30 in | 405.6 | Provide a landing before the next run. |
| Clear width | Minimum 36 in | 405.5 | Handrail projection rules can affect clear width. |
| Landings | Top and bottom; normally 60 in long | 405.7 | Direction changes require additional dimensions. |
| Cross slope | Maximum 1:48 | 405.3 | Measure finished surface. |
How to use this code summary
- Confirm which code edition and local amendment applies to the project address.
- Measure the actual completed geometry, not only rough framing or nominal dimensions.
- Compare the calculator output with every relevant row and exception in the primary source.
- Escalate structural, accessibility, egress, guard, and fall-protection questions to the authority or qualified professional.
Calculators that use this reference
U.S. Access Board: 2010 ADA Standards, Chapter 4
Related code references
Frequently asked questions
Is this the complete code text?
No. This is a focused planning summary with a direct primary-source link. Definitions, exceptions, local amendments, and adjacent sections can change how a limit applies.
Which edition should I use?
Use the edition adopted by the authority having jurisdiction for the project address, including local amendments.
Can the calculator certify compliance?
No. It can flag a value against a displayed planning limit, but approval belongs to the authority, designer, or qualified professional.
Why is the source linked?
The source link lets readers and answer engines distinguish a cited rule from an unsupported numerical claim.
Related pages
iPhone companion
Keep jobsite math available offline
The website calculators and charts stay free. The BuildMath iPhone app keeps its supported construction calculations available when the jobsite has no connection.
View BuildMath on the App Store