How Long Should A Wheelchair Ramp?

The length of a wheelchair ramp for four steps will depend on the total height of the steps from the ground or landing below and the slope ratio. The recommended slope ratio is 1:12, and the average height of a step is 7,5 inches. This means a four-step ramp will need to be thirty feet long.

I’m not sure about you, but I have seen some crazy-steep ramps for wheelchairs that look positively dangerous. They were clearly designed and built by people who don’t have to push themselves up or roll down in a wheelchair. Thankfully, safety standards help those building wheelchair ramps determine how long they should be to avoid steep gradients.

Since steps aren’t all 7,5 inches high, and there isn’t always enough space for a thirty-foot ramp, the slope ratio of ramps differs from ramp to ramp. Below you will find more information on how to calculate the length of a ramp based on the total vertical rise of the steps and the different slope ratios. There’s even a handy table and extra resources to help you learn more.

The Americans with Disabilities Act (ADA) recommends a wheelchair ramp for commercial use should have a maximum slope ratio of 1:12. This means that for every inch of height or vertical rise, you need 12 inches or 1 foot of ramp. However, the ADA suggests that a slope ratio of 1:20 is even more preferable, though it is not always practical.

For ramps for domestic use, the ADA recommends that the slope rate be no steeper than 2:12 (or 1:6). Such steep ramps would be suitable for homes that have limited space for a ramp.

Many other countries also recommend the maximum slope ratio of a wheelchair ramp for non-domestic use to be 1:12. Examples include the United Kingdom, Hong Kong, and South Africa. However, in Australia’s National Construction Code, the maximum slope ratio is 1:8. This means their ramps can be shorter and steeper than in most other countries.

The length of a ramp isn’t measured by the number of steps in a staircase. Instead, it is calculated using the total vertical rise and the slope rate.

To start, you would need to measure the height of the top step down to the ground or platform where the wheelchair ramp will begin to determine how long the ramp should be.

For example, let’s calculate the ramp length based on the average step height. The average step height in the United States is 7.5 inches. So, if you have four steps, the total vertical rise would be 30 inches.

i.e., Vertical rise = 7.5 x 4 = 30 inches

To work out the ramp length based on the ADA recommended slope ratio for non-domestic use, we need to multiply 30 inches by 12.

i.e., Ramp length = 30 x 12 = 360 inches, or 30 feet.

So, based on an average step height of 7.5 inches and a slope ratio of 1:12, a non-domestic wheelchair ramp for four steps will need to be 30 feet long.

A domestic ramp could be as short as 15 feet if you use the same vertical rise of 30 inches for 4 steps, with a slope ratio of 2:12.

As per the ADA, no ramp span for commercial use may exceed 30 feet in length. If the total ramp length needs to be longer, then there needs to be a landing or turning platform for the wheelchair user to rest if needed. This safety standard is recommended but not applicable to residential wheelchair ramps.

As mentioned, the average height of steps on staircases is 7.5 inches. But what about steps that are higher or lower than that? And what if the slope ratio differs from 1:12? Below is a handy table that can help you determine how long a ramp should be for 4 steps based on their heights and slope ratios.

Since vehicles come in all shapes and sizes, it isn’t easy to have a one-size-fits-all standard regarding ramp length. Also, not all vehicles have steps. Another variable is the vehicle’s ground clearance and if the ramp will be from the ground or the curb.

To overcome this, some buses and public transport systems have removed the steps and incorporated a modified suspension to lower the vehicle to curbside height. Other vehicles have hydraulic ramps that lower or unfold for passengers to board or climb off. These ramps are more reliable than hydraulic lifts.

Portable ramps need to be foldable and robust enough to carry the weight of a person in a wheelchair comfortably. So, portable ramps and those for personal use must be designed according to the vehicle’s size, height, and point of entry. With this in mind, they also need to consider the slope ratio of the ramp.

At Estraint, the safety of wheelchair users is our priority. If you need more information on ramps for wheelchairs, we have excellent eBooks and information for you to download and use.

The length of a wheelchair ramp for four steps will depend on the steps’ total vertical rise or height and the slope ratio used. The Americans with Disabilities Act recommends a slope ratio of 1:12 for non-domestic use. Therefore, for average-height steps, a ramp for four steps will need to be thirty feet long for non-domestic use. For domestic use, the ramp can be as short as fifteen feet.