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. SANS 10400-S: no steeper than 1:12, with a landing at least 1.2 m long at the top and bottom of each run. Between landings a 1:12 ramp rises at most 500 mm (6 m long), a 1:15 ramp 665 mm (10 m) and a 1:20 ramp 750 mm (15 m). The clear width is at least 1,100 mm.
Worked example
With these inputs:
- Total rise
- 450 mm
- Slope
- 1:12 (maximum)
the result is:
- Ramp length (slope)
- 5.4 m
- Landings
- 2 (top, bottom)
- Overall length with landings
- 7.8 m
- 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 SANS 10400 (the National Building Regulations) and your local municipality before ordering.