ADA Standards Ramp Calculator

ADA ramp slopes

The 2010 ADA Standards (Americans with Disabilities Act) set out some minimum requirements for new public facilities. As well as including many different accessibility standards, it contains guidelines for ramp construction. In this paragraph, we'll take a closer look at ADA ramp slopes.

According to the ADA standards, the least steep slope shall be used for any ramp. Apart from that information, what exactly does the guideline say?

  • 1:12 is the maximum slope of a ramp for new constructions
ADA max ramp slope for unassisted user - 1:12
  • 1:16 is the comfortable slope
ADA slope for unassisted user, comfortable slope - 1:16
  • 1:20 is the minimum slope - below that value, it's not considered a ramp (thus, e.g., handrails are not needed)
ADA slope for unassisted user, minimum slope - 1:20

In each case, the maximum rise allowed is 30 in (760 mm). These three ADA ramp slope values are preset in our ramp calculator.

If existing sites, buildings, and facilities have space limitations, steeper ADA ramp slopes may be permitted. However, stricter restrictions on the maximum rise apply:


Maximum rise



1:8 to <1:10

3 inches

75 mm

1:10 to <1:12

6 inches

150 mm

Remember that the ADA prohibits slopes steeper than 1:8.

Other ADA ramp requirements

When constructing a ramp, be it for your home, public space, or temporary use, you need to think about a few things other than a ramp slope and rise:

1. Clear width

The minimum clear width of a ramp is 36 in (91.5 cm). Don't forget to take into account the mounting of handrails when designing a ramp.

2. Landings

Every ramp should have level landings at the top and bottom of each section - especially if your ramp has multiple sections (turns). The following landing features are essential:

  • The minimum landing length is 60 in (1525 mm), and the landing's width should be at least as wide as the ramp's run.
ADA ramp requirements: landing size for straight ramp
  • You need to provide enough space for maneuvers: if the ramp construction changes direction (a 90-degree turn), then the minimum landing size is 60 in×60 in:
ADA ramp requirements: landing size for 90 and 180 degree turns

Don't forget to add even more space for switchback ramps.

3. Handrails

Every time a ramp has:

  • a rise greater than 6 in (15 cm) or

  • a run greater than 72 in (183 cm),

Then the handrails are needed on both sides to comply with ADA standards. You will find more details in paragraph 4.8.5 of the ADA Ramp Document

4. Other important factors are:

  • The cross slope (camber) of the ramps cannot exceed 1:50;
  • The ramp should be made out of appropriate material to prevent sliding and slipping;
  • Edge protection and handrail extensions; and
  • Taking into account weather conditions if it's an outdoor ramp (proper drainage).


Use Ramp Calculator Here:


Wheelchairs in Motion Ramp Calculator