ADA ramp requirements

The Americans with Disabilities Act (ADA) requires accessible ramps to have a maximum slope of 1:12 - 1 inch of rise for every 12 inches (1 foot) of horizontal run. A 30" rise requires at least a 30-foot ramp.

Slope vs. grade

Ratio	Percent grade	Degrees	Use
1:12	8.33%	4.8°	ADA max for ramps
1:8	12.5%	7.1°	Residential ramps (not ADA)
1:6	16.7%	9.5°	Steep residential allowed with handrails
1:20	5%	2.9°	Accessible path of travel (gentler)

Landing requirements

The ADA requires a level landing (max 2% cross-slope in any direction) at the top and bottom of every ramp run. For long ramps, a landing is also required at least every 30 feet of horizontal run. Landings must be at least 60 × 60 inches to allow wheelchair users to rest and reposition.

Handrail requirements

ADA requires handrails on both sides of a ramp when the rise exceeds 6 inches. Handrail height must be 34–38 inches above the ramp surface. Handrails must extend horizontally at least 12 inches beyond the top and bottom of the ramp. Gripping surfaces must have a cross-section diameter of 1.25–2 inches.

Ramp materials

Concrete: most durable and permanent; must be broom-finished or have an exposed aggregate surface for slip resistance; expensive to modify after installation.
Aluminum (modular systems): lightweight, portable, corrosion-resistant; most wheelchair accessibility ramps for doorways are aluminum; slip-resistant surface is typically punched or ribbed.
Pressure-treated wood: lower cost; must be covered with non-slip strips or paint; requires regular maintenance and resealing.

Vehicle ramps

Driveway approach: standard vehicle clearance requires ≤10–14° (18–25% grade) for most passenger cars; sports cars and low-profile vehicles may require ≤7°.
Loading dock approach: max 10% grade (1:10) is recommended for forklift and pallet jack safe operation.
Trailer ramps for vehicles: vehicle ground clearance determines safe ramp angle; a typical car transporter ramp is 6–8°.