A ramp for independent wheelchair use should rise no more than 1 inch per 12 inches of run, with a 36-inch minimum clear width and level 60-inch landings at the top and bottom, per sections 405.2 through 405.7 of the ADA 2010 Standards for Accessible Design. A 24-inch porch step needs at least 24 feet of ramp. This site publishes information, not construction advice.
What Are the Exact Dimensions?
Section 405 of the ADA 2010 Standards sets the numbers most builders and inspectors use, and ANSI A117.1, the model accessibility standard many local codes adopt, carries matching figures. The core requirements:
- Running slope: 1:12 maximum, meaning 1 inch of rise per 12 inches of run (ADA 2010 section 405.2). Steeper is harder and less safe; shallower, like 1:16 or 1:20, is easier.
- Cross slope: 1:48 maximum, so the ramp does not tilt sideways (section 405.3).
- Clear width: 36 inches minimum between handrails or edge guards (section 405.5).
- Rise per run: 30 inches maximum before a resting landing is required (section 405.6).
- Landings: 60 inches long at top and bottom, and at least as wide as the ramp; where the ramp changes direction, a 60-by-60-inch landing (section 405.7).
- Handrails: required on both sides when the rise exceeds 6 inches, mounted 34 to 38 inches above the surface (sections 405.10 and 405.8).
- Edge protection: a curb, rail, or barrier preventing a wheel from slipping off, where drop-offs exist (section 405.9).
How Do You Calculate the Ramp Length You Need?
The math is simple, and doing it before you call contractors keeps the project honest.
- Measure the total rise: from the driveway or sidewalk to the top of the door threshold, in inches.
- Divide by 12 for a 1:12 slope. A 30-inch rise needs 30 feet of run.
- Add landings: 5 feet at the bottom, 5 feet at the top, and a 5-by-5-foot landing every 30 inches of rise and wherever the ramp turns.
- If the straight-line distance is too short, plan switchbacks with a 60-by-60-inch landing at each turn.
- Check door swing: the top landing must let the storm door open without pushing the wheelchair off the landing.
Example: a 28-inch rise needs 28 feet of ramp plus landings, roughly 38 to 40 feet of total footprint as a straight run, or about 20 feet of wall with one switchback.
What Makes a Landing Safe?
Landings do three jobs: they give a place to rest, they let a wheelchair user open and pass through a door without rolling backward, and they break long runs. Build them level, with slope no more than 1:48 in any direction for drainage, per section 405.7. At the top landing, size matters most at the door: when a door opens onto the landing, allow enough depth, 60 inches minimum, for a wheelchair to sit clear of the door's swing while someone pulls it open. A common miss is a landing sized only for standing users, which fails on the first rainy day with groceries. In snow and ice country, add a strategy for winter: a covered landing at the door, drainage that keeps water off the surface, and enough width to run a shovel or a heated mat along the walk. Also plan the approach at the bottom — a ramp that ends on soft lawn defeats itself, so land it on a firm pad of concrete or compacted pavers at least as large as the landing itself.
Related stories: Widening Hallways: The Structural Basics · Grab Bar Placement: Heights and What the Standards Say.
How Do Slope Rules Differ for Homes?
Standards diverge by setting, and the differences are worth knowing. The ADA 2010 Standards govern public accommodations and commercial facilities. The Fair Housing Act design requirements, which HUD administers under 24 CFR 100.205, cover covered multifamily housing built for first occupancy after March 1991 and allow steeper ramps, up to 1:8 under certain conditions in that context, than the ADA. ANSI A117.1, adopted in many local building codes, generally matches the 1:12 benchmark. For a private house, none of these binds you legally in most jurisdictions, but a local permit may apply to structural ramps, and 1:12 remains the safe design target for self-propelled wheelchair use.
What About Materials and Surface?
Whatever the material, the surface must be firm, stable, and slip resistant per ADA 2010 section 302.1, and that matters more outdoors, where rain, ice, and leaf mold change everything.
- Concrete: the permanent, lowest-maintenance choice; broom-finish for grip. Typical installed cost for a residential ramp runs roughly $200 to $400 per linear foot, per industry ranges as of 2025.
- Wood: buildable by a carpenter, needs handrails, curbs, and ongoing sealing; roughly $100 to $250 per linear foot.
- Aluminum modular: prefab sections bolted together, relocatable, fast install; roughly $150 to $300 per linear foot depending on configuration.
Prices vary by region and site prep; treat the ranges as planning figures and get itemized local quotes.
What Should You Check Before Building or Buying?
A checklist you can walk with a tape measure:
- Total rise measured from level ground to threshold, in inches.
- Planned run at 1:12 or shallower, with rise kept under 30 inches per run.
- Landings: 60 inches top and bottom, 60 by 60 at turns, clear of door swing.
- Width 36 inches minimum clear, with edge protection along drop-offs.
- Handrails both sides for rises over 6 inches, 34 to 38 inches high, extending 12 inches at the ends, per sections 405.10 and 505.
- Cross slope under 1:48; drainage away from the surface.
- Permit status confirmed with the local building department.
Can Funding Help Pay for a Ramp?
Often, yes, more than for most modifications. Medicare does not cover ramps. But some state Medicaid home and community-based services waivers fund ramps as environmental modifications, the VA's Home Improvements and Structural Alterations benefit has historically covered ramps for eligible veterans up to a per-lifetime cap, and many area agencies on aging and civic organizations, such as volunteer ramp-building programs, install ramps at low or no cost for eligible homeowners. Eligibility is stated program by program; confirm the terms on each program's own page rather than counting on a general rule. This is program information, not a benefits determination for an individual case.
Where Can You Read the Standards Yourself?
The full text of the ramp provisions is public. Section 405 of the ADA 2010 Standards covers slope, width, landings, handrails, and edge protection, and the U.S. Access Board publishes the standards with advisory notes explaining the reasons behind each figure. Read the section before you accept a contractor's design, and compare any modular quote against the same numbers. Local codes vary by jurisdiction, so the building department's word is the final one for permits.