ADA ramp requirements
Every rule for a wheelchair ramp in the ADA Standards, with the section it comes from, and what it means if the ramp is going on your own house.
Last verified
| Requirement | The rule | Section |
|---|---|---|
| Maximum slope | 1:12. One inch of rise for every 12 inches of ramp | 405.2 |
| Maximum cross slope | 1:48, side to side | 405.3 |
| Minimum width | 36 inches clear, measured between handrails | 405.5 |
| Maximum rise per run | 30 inches, then a landing | 405.6 |
| Landings | At the top and bottom of every run, 60 inches long, at least as wide as the ramp | 405.7 |
| Landing where the ramp turns | 60 by 60 inches | 405.7.4 |
| Handrails | Both sides, on any run that rises more than 6 inches | 405.8, 505.2 |
| Handrail height | 34 to 38 inches to the top of the rail | 505.4 |
| Handrail extensions | 12 inches level beyond the top and bottom of each run | 505.10.1 |
| Edge protection | A curb or barrier, or the ramp surface extended 12 inches past the handrail | 405.9 |
| Surface | Stable, firm and slip resistant | 302.1 |
Does the ADA apply to a ramp at your house?
No, in most cases. The US Access Board states that the ADA does not apply to privately owned housing that is not used as a public accommodation, including single family homes, condominiums and apartments. The exception is a home that also runs a business open to the public: the part of the house used for the business is covered, and the part used only as a home is not.
That does not make the numbers irrelevant. Your city or county may still require a permit and set its own rules for a ramp, especially a permanent one, so check with the local building department before you build. And whatever your code says, the ADA figures are the most widely used standard for a ramp that someone will climb in a wheelchair on their own. Every rule on this page is worth meeting at home, and the first one is worth beating.
Slope: 1:12 is a maximum, not a target
A 1:12 slope means one inch of height for every 12 inches of ramp, so a rise of 24 inches needs 24 feet of ramp. The ADA also limits cross slope, the tilt from side to side, to 1:48, which is barely perceptible and stops a chair from drifting toward one edge.
The Access Board's own advice is to use the least slope you can, because 1:12 is still hard work for many people pushing themselves, and harder still for anyone with limited stamina. For a parent in a manual chair, 1:16 or 1:20 is kinder if the yard allows it, but it costs length: at 1:20 the same 24 inch rise needs 40 feet, two thirds longer. The ramp length calculator works out the 1:12 length for your rise and the space it takes up.
There is one exception, and it is narrower than it sounds. In existing buildings where there is genuinely no room, the ADA permits a slope up to 1:10 for a rise of 6 inches or less, and up to 1:8 for a rise of 3 inches or less. Nothing steeper than 1:8 is allowed at all.
| Slope | Maximum rise |
|---|---|
| Steeper than 1:12, up to 1:10 | 6 inches |
| Steeper than 1:10, up to 1:8 | 3 inches |
| Steeper than 1:8 | Not allowed |
Width: 36 inches between the handrails
The clear width of the ramp must be at least 36 inches, and where there are handrails, that 36 inches is measured between them, not between the posts or the edges of the deck. A ramp built 36 inches wide and then fitted with handrails on the inside is too narrow.
Rise and landings
No single run may climb more than 30 inches. Every run needs a level landing at its top and its bottom, and each landing must be:
- at least 60 inches long in the direction of travel
- at least as wide as the widest run leading to it
- 60 by 60 inches where the ramp changes direction, as in an L shape or a switchback
- level, with no slope steeper than 1:48, which is only enough to drain water
At a doorway, the space needed to open the door and get through it can overlap the top landing, so you do not need a separate platform for each. Landings that get wet must be designed so water does not pool.
In practice, the 30 inch limit is why tall porches end up with switchback ramps. A 36 inch rise at 1:12 needs 36 feet of ramp, split into two runs with a landing between them, before counting the landings at each end.
Handrails
Any run that rises more than 6 inches needs handrails on both sides. The rules for the rails themselves:
- Height: the top of the gripping surface 34 to 38 inches above the ramp surface, at a consistent height all the way along
- Continuous: unbroken for the full length of each run, and continuous around the inside of a switchback
- Extensions: 12 inches level beyond the top and bottom of each run, returning to a wall, a guard or the ground so nothing snags on the end
- Clearance: at least 1½ inches between the rail and any wall beside it, room for a hand
- Grip: a round rail 1¼ to 2 inches in diameter, or a shaped rail of similar size, that does not rotate in its fittings
A standard 2 by 4 laid flat is not a compliant handrail; it is far too wide to grip. That is the most common shortcut on homemade wooden ramps.
Edge protection
Both sides of every run and landing need something that stops a wheel or a crutch tip from going over the edge. The ADA allows either of two methods:
- a curb or rail low enough that a 4 inch ball could not roll under it anywhere within 4 inches of the ramp surface, or
- extending the ramp surface at least 12 inches past the inside face of the handrail, so a caster that slips sideways is still on the ramp
Surface
The ramp surface must be stable, firm and slip resistant, and apart from its slope it must have no changes in level: no lips between boards or modules. Smooth painted wood turns slippery when wet, which is why aluminum modular ramps with a textured deck and broom finished concrete are the usual choices.
When you need a ramp at all
Under the ADA, any change in level over half an inch must be ramped. A change of up to a quarter inch can be a plain vertical edge, and between a quarter and half an inch it must be bevelled. That is the boundary where a threshold ramp, a small wedge at a doorway, becomes the right tool rather than a full ramp.
Curb ramps follow different rules
Curb ramps, the short ramps cut into sidewalks at crossings, share the 1:12 slope limit but have their own requirements under section 406: a top landing 36 inches long, flared sides no steeper than 1:10, and on public streets, further rules for detectable warnings. They are a street design matter rather than a home access one, and this page does not cover them.
A checklist for a ramp at home
- Measure the rise from the ground to the top of the threshold, in inches.
- Work out the length at 1:12 with the ramp calculator. If there is room for two thirds more, 1:20 is easier to climb.
- If the rise is over 30 inches, plan the landings and turns before choosing a ramp.
- Allow 36 inches clear between handrails, not 36 inches of deck.
- Ask your building department whether a permit is needed.
- Check whether a program will pay for it. The funding guide covers VA grants, Medicaid waivers and USDA repair grants.
Every requirement on this page is taken from the 2010 ADA Standards for Accessible Design as published by the US Access Board: sections 302 and 303 in Chapter 3 (opens in a new tab), ramps (405) and curb ramps (406) in Chapter 4 (opens in a new tab), and handrails (505) in Chapter 5 (opens in a new tab). Coverage of private homes is from the Access Board's guide to using the ADA Standards (opens in a new tab). This page explains the standard; it is not legal advice, and your local building code may add to it.