Braillito Maps · Accessibility guides
ADA stair requirements: risers, treads, nosings and landings
Stairs are never part of an accessible route, so a wheelchair user needs a ramp, an elevator or a lift instead (2010 ADA Standards, 402.2). But plenty of people with disabilities do use stairs: people who walk with a cane, crutches or a walker, people with low vision, people who tire easily. For them, the 2010 ADA Standards say how a stair is built in section 504, and which stairs have to follow it, mainly in section 210. These are those requirements, each with its section of the standard.
This is a summary. The official 2010 ADA Standards for Accessible Design are the reference.
Which stairs the ADA covers
The main rule: interior and exterior stairs that are part of a means of egress comply with section 504 (2010 ADA Standards, 210.1). A means of egress is the way out of a building; for its details, section 207 of the Standards sends you to the International Building Code (2010 ADA Standards, 207.1).
Four kinds of stairs are left out of section 504:
- Detention and correctional facilities: stairs outside public use areas (2010 ADA Standards, 210.1, exception 1).
- Alterations: stairs between levels that are already connected by an accessible route. They still get handrails that comply with section 505 when the stairs are altered (2010 ADA Standards, 210.1, exception 2).
- Assembly areas: aisle stairs, the steps between rows of seats (2010 ADA Standards, 210.1, exception 3).
- Playgrounds: stairs that connect play components (2010 ADA Standards, 210.1, exception 4).
Pool stairs are covered through another section. A swimming pool has at least two accessible means of entry, and pool stairs complying with section 1009.6 are one of the options, although at least one of the means of entry has to be a pool lift or a sloped entry (2010 ADA Standards, 242.2). Those pool stairs comply with section 504, except that their risers do not have to be 4 to 7 inches high as long as they are uniform (2010 ADA Standards, 1009.6.1). Their handrails are 20 to 24 inches (510–610 mm) apart, and they do not need the bottom extension of section 505.10.3 (2010 ADA Standards, 1009.6.2). The pool lift and the other means of entry are in ADA pool lift requirements.
For stairs that are not part of a means of egress, the standard itself notes that it does not require handrails, but state or local building codes may require handrails or guards (2010 ADA Standards, advisory 210.1).
Stairs and ramps work together rather than replace each other. The accessible route is made of walking surfaces no steeper than 1:20, doorways, ramps, curb ramps, elevators and platform lifts, with no stairs on the list (2010 ADA Standards, 402.2). And the advisory on ramp slope recommends adding stairs next to a ramp wherever possible, for people for whom distance is a greater barrier than steps, such as people with heart disease or limited stamina (2010 ADA Standards, advisory 405.2). How steep that ramp may be is in the ADA ramp slope guide.
Riser height and tread depth
Section 504 sets the shape of every step. The riser is the vertical face of a step and the tread is the part you stand on:
| Element | Requirement | Section |
|---|---|---|
| Riser height | 4 inches (100 mm) minimum and 7 inches (180 mm) maximum | 2010 ADA Standards, 504.2 |
| Tread depth | 11 inches (280 mm) minimum | 2010 ADA Standards, 504.2 |
| Uniformity | all steps on a flight have the same riser height and the same tread depth | 2010 ADA Standards, 504.2 |
| Open risers | not permitted | 2010 ADA Standards, 504.3 |
| Tread surface | stable, firm and slip resistant, with no changes in level; a slope of up to 1:48 is allowed | 2010 ADA Standards, 504.4 and 302.1 |
| Wet conditions | treads and landings exposed to water are designed so that water does not accumulate | 2010 ADA Standards, 504.7 |
Uniform means within one flight: every riser the same height and every tread the same depth (2010 ADA Standards, 504.2). As with every dimension in the Standards, conventional industry tolerances apply to construction, though not to design work (2010 ADA Standards, 104.1.1 and advisory 104.1.1). The 4-inch minimum matters too, because a very low step is easy to miss with the eyes or with the tip of a cane.
An open riser is a step with a gap instead of a back, the kind you can see through on many modern and outdoor stairs. Section 504 does not allow them (2010 ADA Standards, 504.3).
The tread surface follows the general rules for floors. The standard defines the three words: a stable surface returns to its original condition once a contaminant or a force is removed, a firm surface resists indentation, and a slip-resistant one gives enough friction to walk safely (2010 ADA Standards, 302.1 and advisory 302.1). Carpet on treads is securely attached, with a pile no higher than 1/2 inch (13 mm) and trim along its exposed edges (2010 ADA Standards, 302.2). A grating or any other opening in a tread does not let a sphere larger than 1/2 inch (13 mm) pass through, and long openings run perpendicular to the dominant direction of travel (2010 ADA Standards, 302.3).
ADA stair nosing requirements
The nosing is the front edge of a tread, where the foot lands first going up and the heel leaves last going down. Section 504.5 sets four limits on it:
- Rounded edge: the radius of curvature at the leading edge of the tread is 1/2 inch (13 mm) at most (2010 ADA Standards, 504.5).
- Underside: a nosing that projects beyond the riser has the underside of its leading edge curved or beveled, so there is no square lip underneath (2010 ADA Standards, 504.5).
- Sloped risers: a riser may slope back under the tread, up to 30 degrees from vertical (2010 ADA Standards, 504.5).
- Projection: the nosing projects 1 1/2 inches (38 mm) at most over the tread below (2010 ADA Standards, 504.5).
For people with low vision, the standard recommends visual contrast on tread nosings, or on the leading edges of treads without nosings, so that each step is easier to see. It is a recommendation in an advisory note, not a requirement (2010 ADA Standards, advisory 504.4). Section 504 does not ask for a tactile warning surface at the top of a stair; the textured surface the Standards call detectable warnings is explained in the guide to truncated domes.
Handrails on ADA stairs
Stairs covered by section 504 have handrails that comply with section 505 (2010 ADA Standards, 504.6). The points that matter most on a stair:
- Both sides: stairs have a handrail on each side (2010 ADA Standards, 505.2).
- Continuous: each handrail runs the full length of each flight, and on switchback or dogleg stairs, the inside handrail continues from one flight to the next (2010 ADA Standards, 505.3).
- Height: 34 to 38 inches (865–965 mm) to the top of the gripping surface, measured vertically from the stair nosings, at a consistent height (2010 ADA Standards, 505.4).
- Top extension: at least 12 inches (305 mm) horizontally above the landing, starting directly above the first riser nosing (2010 ADA Standards, 505.10.2).
- Bottom extension: at the slope of the stair, for a horizontal distance of at least one tread depth beyond the last riser nosing (2010 ADA Standards, 505.10.3). With treads of 11 inches or more, that is at least 11 inches (2010 ADA Standards, 504.2).
The continuous inside handrail of a switchback or dogleg stair needs no extension at the turn, and in alterations a full extension is not required where it would be hazardous because of the layout (2010 ADA Standards, 505.10, exceptions 1 and 3). The diameter of the rail, its clearance from the wall and how a handrail is checked by hand are in the guide to ADA handrail requirements.
What section 504 does not set
People often look for figures that are not in the ADA stair section, and it is worth saying so plainly:
- Stair width. Section 504 has no minimum width. For accessible means of egress, section 207.1 sends you to the International Building Code, 2000 edition with its 2001 Supplement or 2003 edition (2010 ADA Standards, 207.1). We have not read those codes, so this guide gives no width.
- Landings and number of steps. Section 504 sets no landing size and no maximum number of risers per flight. It mentions landings only for water, which must not accumulate on them, and for the handrail extensions above them (2010 ADA Standards, 504.7, 505.10.2).
- Local rules. State and local building codes may add their own requirements; the standard notes it for handrails and guards on stairs that are not part of a means of egress (2010 ADA Standards, advisory 210.1).
Outside section 504, the Standards do add three things that touch a stair:
- The sign. Doors at exit stairways are identified by tactile signs, with raised characters and braille (2010 ADA Standards, 216.4.1, 703.1 and 703.2). Where those signs go and how they are read is in the guide to braille signage.
- A route beside a new stair. In alterations and additions, where a stair is added where none existed and its installation needs major structural modifications, an accessible route is provided between the levels the stair serves, unless one of the exceptions of section 206.2.3 applies (2010 ADA Standards, 206.2.3.1).
- The space under the stair. Vertical clearance is at least 80 inches (2030 mm), and where it is lower, as under the sloped underside of a stair, a guardrail or other barrier is provided with its leading edge 27 inches (685 mm) above the floor at most, low enough for a long cane to detect it (2010 ADA Standards, 307.4 and Figure 307.4).
How to check a stair on site
A tape measure is enough for the main points. It does not replace an inspection, but it tells you what a stair will be like to climb:
- Measure two or three risers. Each one is 4 to 7 inches high, and all of them in a flight are the same (2010 ADA Standards, 504.2).
- Measure a tread's depth: at least 11 inches (2010 ADA Standards, 504.2). The Standards do not say where the measurement starts. On a stair with projecting nosings, measuring from the front edge of one tread to the front edge of the next gives the smaller figure, so it is the safe reading.
- Look between the steps. If you can see through the back of a step, the stair has open risers, which section 504 does not allow (2010 ADA Standards, 504.3).
- Run a finger under the front edge. A nosing that sticks out more than 1 1/2 inches, or that has a sharp, square underside, does not match section 504.5 (2010 ADA Standards, 504.5).
- Count the handrails and measure one. One on each side, 34 to 38 inches above the nosings (2010 ADA Standards, 505.2 and 505.4).
- Look at the ends. At the top, the rail continues at least 12 inches flat; at the bottom, it continues sloping for one more tread (2010 ADA Standards, 505.10.2 and 505.10.3).
Stairs in Braillito Maps
Braillito Maps is a community map where each place answers ten questions: step-free entrance or ramp, wide doorway, accessible restroom, accessible parking, tactile paving, braille signage, braille menu, audible signals, guide dogs welcome and a quiet environment. Each answer is yes, no or no data, and the place gets a score out of ten, one point for each yes.
Stairs are not a question of their own. They belong with the first one, step-free entrance or ramp: a café with three steps at the door and no ramp, lift or level entrance is a no, however well built the steps are, because a wheelchair user cannot get in. If there is a ramp or a level entrance next to the steps, it is a yes.
Two more questions often come up on a stair. Braille signage covers the tactile signs at exit stairways (2010 ADA Standards, 216.4.1), and tactile paving covers a textured guide on the floor for cane users. What this guide adds is what to look at when you get there: uneven or open steps, or a stair with a handrail on one side only, are not what sections 504 and 505 describe, and for someone with a cane, a walker or low vision they can decide whether the visit goes well. The ADA ramp calculator works out how long a ramp beside those steps would have to be.
Frequently asked questions
What is the maximum riser height under the ADA?
7 inches (180 mm). Risers are also at least 4 inches (100 mm) high, and all the risers in a flight are the same height (2010 ADA Standards, 504.2).
What is the minimum ADA stair tread depth?
11 inches (280 mm), with the same depth for every tread in the flight (2010 ADA Standards, 504.2). Open risers are not permitted (2010 ADA Standards, 504.3).
What are the ADA stair nosing requirements?
The leading edge of the tread has a radius of 1/2 inch (13 mm) at most; a projecting nosing has a curved or beveled underside and projects 1 1/2 inches (38 mm) at most over the tread below; and risers may slope under the tread up to 30 degrees from vertical (2010 ADA Standards, 504.5).
Does the ADA set a size for stair landings?
No. Section 504 sets no landing size and no maximum number of risers per flight. It mentions landings only so that water does not accumulate on them, and for the handrail extension above the top landing (2010 ADA Standards, 504.7 and 505.10.2). For accessible means of egress, the 2010 Standards refer to the International Building Code (2010 ADA Standards, 207.1), which this guide has not summarized.
Which stairs have to meet the ADA stair requirements?
Interior and exterior stairs that are part of a means of egress. Section 210.1 leaves out stairs outside public use areas in detention facilities, aisle stairs in assembly areas, stairs that connect play components and, in alterations, stairs between levels already connected by an accessible route, which still get compliant handrails when altered (2010 ADA Standards, 210.1). Pool stairs used as an accessible means of entry to a swimming pool also comply with section 504, with an exception for riser height as long as the risers are uniform (2010 ADA Standards, 242.2 and 1009.6.1).
What is the minimum ADA stair width?
Section 504 does not set one. For accessible means of egress, the 2010 Standards refer to the International Building Code (2010 ADA Standards, 207.1), which this guide has not summarized.
More accessibility guides
- ADA handrail requirements: handrail height, diameter, clearance from the wall and the extensions at ramps and stairs.
- ADA ramp slope: the 1:12 rule, width, landings, handrails and edge protection.
- ADA pool lift requirements: how many means of entry a pool needs, and the seat, height, capacity and controls of a pool lift.
- Braille signage: which signs need braille under the ADA, how high they go, on which side of the door, and the size of the dots.
- ADA compliance: a checklist for small businesses, with the 2010 Standards section behind each item.
- All accessibility guides
Sources
Every figure in this guide comes from one of these official texts, which we read in October 2026.
- 2010 ADA Standards for Accessible Design. U.S. Department of Justice, published September 15, 2010; required for new work since March 15, 2012.
Braillito Maps
Find places with ramps, accessible toilets or tactile paving near you in Braillito Maps
In Braillito Maps, every place answers ten questions. One is the ramp: whether you can get in without steps, by ramp or at street level. It is built by the people who need it, and every place gets a score out of ten.
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