Ramp Slope Calculator – Calculate Ramp Angle, Gradient & Length

Design accessible and safe ramps with our Ramp Slope Calculator. Enter the rise and run to calculate slope percentage, gradient ratio, and ramp angle — ensuring ADA or building code compliance for wheelchair ramps and loading docks.

Ramp Dimensions

Rise (height)

Run (horizontal length)

Unit

Quick ADA Reference:

Max Slope

1:12 (8.33%)

Max Rise

30" per run

Min Width

36"

Results

Enter dimensions and click Calculate to see results

ADA Ramp Requirements

Slope Guidelines:

Maximum slope: 1:12 (8.33%) - 1" of rise for every 12" of run
Recommended slope: 1:16 (6.25%) or gentler for easier use
Minimum slope: 1:48 (2.08%) for drainage

Additional Requirements:

Minimum width: 36" clear width
Landings: Required every 30" of rise
Handrails: Required on both sides if slope > 1:20
Edge protection: Required on open sides

Frequently Asked Questions

What is the ADA maximum slope for a wheelchair ramp?

The ADA requires a maximum slope of 1:12, meaning 1 inch of rise for every 12 inches of run. This equals 8.33% grade or about 4.8 degrees. Steeper ramps are not permitted for new construction.

How long does my ramp need to be?

For every inch of rise, you need at least 12 inches of ramp length. A 24-inch rise requires a minimum 288-inch (24-foot) ramp. Always measure the total vertical height from ground to landing.

When are handrails required?

Handrails are required on both sides when the slope exceeds 1:20 (5%). Since ADA ramps are typically 1:12, most ramps will need handrails. They must be 34-38 inches above the ramp surface.

Do I need landings on my ramp?

Yes. A level landing is required at the top and bottom. Intermediate landings are needed every 30 inches of rise. Landings must be at least 60 inches long and as wide as the ramp.

What is the minimum width for a ramp?

The ADA requires a minimum clear width of 36 inches between handrails. Wider ramps (48-60 inches) allow two wheelchairs to pass. Check local building codes as some jurisdictions require more.

Other Free Tools

Search tools