liteRampPortable Wheelchair Ramps and Scooter Ramps

How to Select Portable Wheelchair Ramps

Skip this page if you are having a permanent or modular ramp installed. In those cases, a contractor would visit your site and make plans accordingly. Here's a list of different options of wheelchair ramps. Portable wheelchair ramps are a different story. They can range fom 1 foot to 12 feet in length, and, they don't follow ADA code. In this guide, we'll help you to choose the right ramp.


Let's start with width first because it's simple. Obviously, the width of your equipment (measured at wheel base) must fit within the ramp. Almost all portable ramp are made to 30" wide. Why? Because it's the maximum side-door opening width for most US mini vans, where these ramps are used. The average width of a wheelchair is 26-27". So, width is rarely the problem. Most foreign mini vans have curved doors - wide at the top but narrow at the bottom. You won't be able to load a wheelchair through the side door. So you must use the back door for the following vans: RV's and mobile homes are known to have narrow doors too.

Turn Space

Make sure you have at least 3-4 feet of room at both the entrance end and the exit end of the ramp to turn your wheelchair. If the ramp lands on your drive way or sidewalk, if it too close to a wall? If ramp goes from your garage to your mudroom, is your washer or dryer blocking the way?

The 6:1 Incline

Now you need to choose a ramp length. The rule of thumb is called the 6:1 ratio:

For every inch of vertical rise, use 6" of ramp length


Obviously, the 6:1 ratio will not meet ADA's requirement of 12:1. So what's going on here? First of all, ADA is a building code. But portable wheelchair ramps are not considered building modification. Therefore, they do not have to meet ADA code. Secondly and most importantly, 6:1 incline has worked for more than 90% of our customers over the years under just about any circumstances - manual wheelchairs, power wheelchairs, scooters, walkers, and even animals like dogs and mini horses.

An incline steeper than 6:1 is more likely to cause the follwoing problems: Many electrical wheelchair and scooter manufacturers report the maximum allowable incline for their equipment in degrees of angle. In the calculator down below, type in your vertical rise in inches and a ramp length in foot, click the calculate button, the degree of incline will be calculated. Or you can leave the ramp length field empty, type in an incline degree, and let the calculator figure out the ramp length for you.

Note: The calculator requires JavaScript. Enable it if you get a prompt from the browser.

Enter vertical rise (inches)              
Enter ramp length (feet)                  
Ramp Angle (degrees)                      

Note: 12:1 incline = 4.8 degrees. 6:1 incline = 9.6 degrees.

The 6:1 rule needs to be strict for small rises but relaxed for large rises. An increase of 1" on a 4" threshold is 25%, but only 8% for two steps with 12" rise.

Typical rises for every ramp length are listed in the table below:
Ramp Size
Typical Rise

For automobiles:
side doors of mini vans
back doors of mini vans
side doors of full-size vans
back doors of full-size vans
back doors of small SUV's
back doors of large SUV's
tail gates of small pickup trucks
tail gates of full-size pickup trucks


If your ramp runs across multiple vertical rises in a roll, it needs to clear all the steps in between or it'll have a clearance problem.

It's best to explain it in an example:

Let's say from the side walk, you go up two 7" tall steps onto a porch, which is 3' long (away from your door), then, you need to go up another 4" threshold into the door. How long of a ramp do you need? The total vertical rise is 7"+7"+4" = 18". An 8' ramp should be adequate. But can the 8' ramp reach the threshold without hitting the porch in the middle?

Short of a yardstick, the calculator below will give you the answer. In it, enter 4 for A, 36 for B, and 14 for C, then click the calculate button. The minimum ramp length should say 13.8 feet. In other words, an 8' ramp won't clear the porch. The right choice is to use a 7' ramp for the porch and a 2' ramp for the threshold.

Enter rise for upper stair (inches)        A=
Enter length of lower stair (inches)      B=
Enter rise for lower stair (inches)         C=  
Minimum Ramp Length (feet)

The following calculator would cover even more stairs:

Enter rise for upper stair (inches)        A=
Enter length for middle stair (inches)   B=
Enter rise for middle stair (inches)       C=
Enter length of lower stair (inches)      D=
Enter rise for lower stair (inches)         E=  
Minimum Ramp Length (feet)

Still need help?

We can help you choosing the right wheelchair ramp. Please feel free to contact us: 1-800-561-3576.