About this calculator
How long an access ramp must be for a given rise and slope, and how many landings it needs.
How it’s calculated
Run = rise × slope ratio. ADA: 1:12 maximum, at most 30" of rise per run, landings at least 60" long.
Worked example
With these inputs:
- Total rise
- 24 in
- Slope
- 1:12 (ADA maximum)
the result is:
- Ramp length (slope)
- 24'
- Landings
- 1 (incl. top)
- Overall length with landings
- 29'
- Angle
- 4.76°
Tips from the trade
- A gentler slope than the maximum is much easier for users.
- Handrails are required on both sides of most ramps.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and local building codes before ordering.