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:

- Toyota Sienna
- Honda Odessy
- Nissan Quest
- Hyndai Santa Fei

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?

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:

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:

For automobiles:

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:

- Difficulty to push up a manual chair
- Power chairs and scooters bottom out
- Power chairs and scooters stall on the ramp
- Transport wheelchairs bottom out due to low ground clearance
- Hard to walk up in a walker
- Animals become scared and refuse to get on

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

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

2'

4"

3'

6"

4'

8"

5'

10"

6'

11-13""

7'

14-17"

8'

18-24"

10'

25-32"

For automobiles:

Application

Ramp

side doors of mini vans

6'

back doors of mini vans

7'

side doors of full-size vans

8'

back doors of full-size vans

8'

back doors of small SUV's

7'

back doors of large SUV's

8'

tail gates of small pickup trucks

8'

tail gates of full-size pickup trucks

10'

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.

The following calculator would cover even more stairs:

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.

The following calculator would cover even more stairs:

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