The Americans with Disabilities Act (ADA) requires a 1:12 slope ratio for commercial ramps (ramps used in public spaces). This means that for every 1 inch of rise, 12 inches of ramp are required. For example, if an entryway is 36 inches high, you will need a ramp that is at least 36 feet long.

How do you size a ramp?

For commercial use when somebody is sitting in the wheelchair or scooter while it climbs the ramp, ADA recommends a 1:12 slope, which means that every 1″ of vertical rise requires at least 1′ (12″) of ramp length (5 degrees of incline). Example: A 24″ rise requires a minimum ramp length of 24′ (288″) (24 divided by 1).

What size ramp do I need for 5 steps?

A 5 inch rise requires a 5 foot ramp, a 12 inch rise requires a 12 foot ramp and so on. The ADA recommends this slope for long home ramps as well as commercial ramps.