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 a doorway transition, compare threshold ramps and door clearances. For access between floors, compare straight and curved stair lifts and grab bar placement. 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.