Wheelchair Ramp Length Calculator
Figure out how long a ramp needs to be before you call a contractor for pricing. Measure the rise — the vertical height from the ground to the top of the step, porch, or door threshold — and we'll calculate the ramp length at the ADA-recommended 1:12 slope, plus two steeper options for comparison.
Measuring in feet? Multiply by 12 first (2 ft = 24 in).
| Slope | Ramp length | Notes |
|---|---|---|
| 1:12 (ADA) | — | Maximum slope for a permanent, wheelchair-accessible ramp. |
| 2:12 | — | Steeper, shorter — common on portable ramps, not ADA-compliant. |
| 3:12 | — | Too steep for most wheelchair users; shown for comparison only. |
Why 1:12?
The Americans with Disabilities Act (ADA) sets 1:12 as the maximum running slope for a wheelchair-accessible ramp: no more than 1 inch of rise for every 12 inches (1 foot) of ramp length, roughly an 8.3% grade. Because a foot of ramp is needed for every inch of rise, a 24-inch rise needs a 24-foot ramp. Steeper ramps like 2:12 or 3:12 take up less space, but they're harder and more dangerous to use for someone self-propelling a wheelchair or pushing one uphill, and they don't meet ADA or most local building codes for a permanent ramp.
Landing requirements
- A level landing at least 5 ft × 5 ft is required at the top and bottom of every ramp.
- Each ramp run can rise a maximum of 30 inches before requiring an intermediate landing — at 1:12 slope, that's every 30 feet of ramp length.
- Landings must be at least as wide as the ramp itself, and wider where the ramp turns a corner.
Next steps
Ramp length is only part of the cost — material, railings, and landings matter too. See our wheelchair ramp cost guide for pricing, or go straight to Atlanta wheelchair ramp installers to get connected with a vetted local contractor.
Prefer to talk it through? Call (404) 602-2998 and we'll help you figure out what your home needs.