Wheelchair ramp calculator
Ramp length and landings to ADA
The height from the lower level to the upper one.
Checked against the 2010 ADA Standards for Accessible Design, sections 403.3 and 405. Local codes and other standards can be stricter, so confirm before you build. View the source
Result
Your answer appears here as you type.
About this tool
Enter the height to climb and get the ramp length, the number of runs and landings, and whether handrails are needed — checked against the 2010 ADA Standards.
How the ramp rules work
This calculator applies the 2010 ADA Standards for Accessible Design, the accessibility rules used in the United States. Other countries set their own limits, often similar but not the same, so if you are building elsewhere, use it for planning and check the local regulations.
The main limits
| Rule | Limit |
|---|---|
| Running slope | No steeper than 1:12, which is 8.33% or 4.76° |
| Rise of one run | At most 30 in (760 mm) before a landing |
| Landings | At least 60 in (1,525 mm) long, at the top, at the bottom and between runs |
| Clear width | At least 36 in (915 mm) between handrails |
| Handrails | On both sides of any run that rises more than 6 in (150 mm) |
| Cross slope | No steeper than 1:48 |
A surface at 1:20 or gentler is a walking surface, not a ramp, so the ramp rules for runs, landings and handrails do not apply. In existing buildings where space is limited, the Standards allow a steeper slope for a small rise: up to 1:10 for a rise of 6 in (150 mm) at most, and up to 1:8 for 3 in (75 mm).
Worked examples at 1:12
- A rise of 24 in needs 288 in of ramp, 24 ft, in a single run, with landings at both ends and handrails on both sides.
- A rise of 36 in is more than one run may climb, so it is split into 2 runs of 18 in, each 216 in long, with a 60 in landing between them: 492 in, about 41 ft, before the top and bottom landings.
Measure the rise from the lower surface to the upper one, and the run horizontally, not along the slope. To check a ramp that is already built, switch to Check a ramp, or lay a phone on it and read the slope with the inclinometer.
Frequently asked questions
What is the maximum slope for a wheelchair ramp?
Under the 2010 ADA Standards used in the United States, a ramp can be no steeper than 1:12: one unit of rise for every 12 units of horizontal run. That is a grade of 8.33%, or about 4.76°.
A gentler slope is easier for everyone to use, so 1:12 is a maximum rather than a target. In existing buildings where there is no room for a full-length ramp, the Standards allow a steeper slope for a very small rise only.
How long does a wheelchair ramp need to be?
At the maximum slope of 1:12, multiply the rise by 12: a rise of 24 in needs 288 in of ramp, which is 24 ft, measured horizontally.
Then add the landings. Each run may climb at most 30 in (760 mm), so a taller rise is split into several runs with a level landing of at least 60 in (1,525 mm) between them, plus landings at the top and bottom. Enter your rise above for the full layout.
When does a ramp need handrails?
Under the ADA Standards, a ramp run that rises more than 6 in (150 mm) needs handrails on both sides. The clear width between them must be at least 36 in (915 mm).
Splitting a long ramp into shorter runs does not remove the requirement, because it applies to each run that rises more than that. The calculator above tells you whether your ramp needs them.
Do the ADA ramp rules apply outside the United States?
No. The ADA Standards are US rules. Other countries set their own requirements for ramp slope, landings and handrails in their building regulations and accessibility standards, and the limits are often similar but not identical.
You can still use this calculator to plan a ramp anywhere, in inches or millimetres, but check the final design against the rules where you build. For the angle or grade of a slope in general, the slope calculator converts between degrees, percent and ratios.
Guides
About these measurements
Readings are estimates taken from rendered pixels and consumer device sensors. Do not rely on them for structural engineering, surveying, manufacturing inspection, navigation, or medical decisions. Check anything safety-critical with a calibrated instrument.
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