The steepest slope that an ADA ramp can have is 1:12 which means for every inch of threshold rise, the ramp must be at least 12 inches (one foot) long. If you’re unsure about how to do the calculations, use the ramp slope calculator.
The length of the ramp is directly related to the height between the ground and the bottom of the door along with the required slope. For example, the door on your building is 40 inches above the ground. To make sure that your ramp is not steeper than the 1:12 ratio, your ramp needs to be 40 feet long.
Number of Resting Platform Landings
Following the ADA ramp requirements, the maximum rise for a single ramp run is 30 inches. That means that maximum length is 30 feet, so one additional platform landing is required for every additional 30 feet of ramp. Why? Because the landings serve as resting areas, and the Americans with Disabilities Act determined that after 30 feet of continuous run, a resting area is needed.
|Ramp Length (ft.)||Landings Required|
- Width: the landing must be at least as wide as the widest ramp run that connects to the landing.
- Length: the landing length must be at least 60 inches without obstruction.
- Change in direction: if the ramp changes direction, you need a landing with a clear space that is at least 60 inches by 60 inches.
- Doorways: if there are doorways that lead onto a landing, see the following ADA ramp landing requirements.
Clearance between handrails
The minimum clearance between the ramp handrails is 36 inches, so a wheelchair can fit between the handrails with ease. View all ADA ramp handrail requirements, including length, perimeter, location above the walking surface, and more.
Balusters are required on ADA ramps to provide protection against falling. The balusters must not be spaced farther than 4″ apart from one another so that a child cannot slip through the space.
The guardrail, which is different than the handrail, must be at least 42 inches from the walking surface to prevent people from falling over the side of the ramp.
Edge protection is required along the edges of an ADA ramp run and landings. There are two types of edge protection to choose from:
- Extended ground surface: the ramp and landing walking surface must extend at least 12 inches past the inside edge of the handrail
- Barrier / kickplate: you cannot have a gap larger than 4 inches between the ramp or kickplate and the bottom of the guardrail.