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. Accessible ramps under the National Building Code and CSA B651 are no steeper than 1:12, with level landings at least 1.5 m (about 5 ft) long at the top, the bottom and at least every 9 m (about 30 ft) of run.
Worked example
With these inputs:
- Total rise
- 24 in
- Slope
- 1:12 (maximum)
the result is:
- Ramp length (slope)
- 24'
- Landings
- 1 (incl. top)
- Overall length with landings
- 28' 11-1/16"
- 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 the building code adopted in your province before ordering.