The 2010 ADA Standards set a maximum ramp slope of 1:12, meaning 1 inch of rise needs 12 inches of ramp. A 24-inch rise therefore needs a 24-foot ramp. Each run may rise no more than 30 inches before a level landing at least 60 inches long, the clear width must be at least 36 inches, and ramps rising more than 6 inches need handrails on both sides. Homes are not required to follow ADA rules, but they are a good guide for independent use.
Rise determines everything about a ramp: its length, landings and type.
Length by rise (1:12)
| Rise | Minimum ramp length |
|---|---|
| 3 in | 3 ft |
| 6 in | 6 ft |
| 12 in | 12 ft |
| 18 in | 18 ft |
| 24 in | 24 ft (with landing rules) |
| 30 in | 30 ft |
Measure the rise as the vertical distance from the ground where the ramp will start to the top of the threshold.
ADA basics
| Item | 2010 ADA Standards |
|---|---|
| Max slope | 1:12 |
| Max rise per run | 30 in |
| Landings | At least 60 in long, at top, bottom and changes of direction |
| Clear width | At least 36 in between handrails |
| Handrails | Both sides if rise exceeds 6 in |
| Edge protection | Required to stop wheels slipping off |
Ramp types
- Threshold ramps: small rises at doorways.
- Portable folding ramps: short rises, travel, assisted use.
- Modular aluminum ramps: bolt-together systems with landings and rails; can be moved later.
- Permanent wood or concrete: may need a permit.
Planning
Mobility scooters and power chairs are heavier and longer than manual chairs, so check the ramp’s weight rating and landing size. Turning landings need more space.
For indoor access, see stair and platform lifts and grab bars. For the chair itself, see measuring for a wheelchair.
Browse home accessibility.
Common questions
How long does a wheelchair ramp need to be?
At a 1:12 slope, 1 foot of ramp per inch of rise. Measure the rise from the ground to the top of the threshold.
Can a home ramp be steeper than 1:12?
Homes are not bound by the ADA, and portable ramps are often used steeper with an assistant. For self-propelling users and scooters, 1:12 or gentler is safer.
Does a ramp need handrails?
Under ADA standards, yes, on both sides when the rise is more than 6 inches. Handrails help at home too.
What is a threshold ramp?
A small wedge that bridges a door threshold or single step, typically a few inches high.