How long does your ramp need to be? Measure the rise – the height from the ground to the top of the step, landing or doorway threshold – and enter it below. The calculator shows the ramp length you need at the slope you choose.
How to measure
- Set a straightedge or level on the top step, porch or threshold so it sticks out past the edge.
- Measure straight down from the bottom of the straightedge to the ground where the ramp will sit. That number is your rise.
- Check the ground where the ramp will end. If it slopes downhill away from the house, the ramp will need to be a little longer.
Which slope should I pick?
- 1:12 – 1 inch of rise for every 12 inches of ramp. This is the ADA guideline and the best choice for someone pushing their own manual wheelchair.
- 1:10 – a little steeper and shorter. Common for home ramps when space is tight.
- 1:8 and 1:6 – steeper slopes for power chairs and scooters with an attendant, or for loading equipment. Use only with a helper.
Always follow the slope limits in your wheelchair or scooter owner's manual, and check local building codes for permanent installations.
Quick reference chart
| Rise | 1:12 | 1:10 | 1:8 | 1:6 |
|---|---|---|---|---|
| 2 in | 2 ft | 1.7 ft | 1.3 ft | 1 ft |
| 4 in | 4 ft | 3.3 ft | 2.7 ft | 2 ft |
| 6 in | 6 ft | 5 ft | 4 ft | 3 ft |
| 12 in | 12 ft | 10 ft | 8 ft | 6 ft |
| 18 in | 18 ft | 15 ft | 12 ft | 9 ft |
| 24 in | 24 ft | 20 ft | 16 ft | 12 ft |
| 30 in | 30 ft | 25 ft | 20 ft | 15 ft |
Ramp length does not include level landings at the top and bottom. Under ADA guidelines, a single ramp run should not rise more than 30 inches before a level resting platform.
Not sure? Let us measure it for you.
ALLmobility offers a free on-site evaluation in the Dayton area. We'll measure, recommend the right ramp and install it.
This calculator is a guide for rise and length only. Use a helper on any ramp steeper than your mobility device allows.