Ramp Calculator
Calculate ramp length and grade, with the NCC housing gradient limit explained.
Estimate only — not a substitute for a licensed tradesperson, a certified engineer, or sign-off from your local building surveyor. Verify against current standards and site conditions before ordering materials or starting work.
Result
- Minimum run length
- 4,200mm
- Resulting grade
- 7.14%
CORRECTED 2026-08-31. The previous note cited a 'commonly-cited' 1:14 AS 1428.1 figure, which was never verified against the standard and pointed at the wrong rule for a house. Verified against NCC 2022 Housing Provisions on ncc.abcb.gov.au: clause 11.2.3 requires an external ramp to be not steeper than 1:8, and clause 11.2.5(1)(b) requires an associated landing to be not steeper than 1:50. AS 1428.1 governs ramps in buildings REQUIRED TO BE ACCESSIBLE (via NCC Volume One), which is a different and stricter rule - AS 1428.1 is a licensed standard and its figures are deliberately not reproduced here. The 1:14 default below is tighter than the housing limit and has deliberately been kept, but confirm which rule applies to your building class, and check landings, handrails and run-length limits separately.
What this is based on
NCC Housing Provisions · 11.2.3
An external ramp serving an external doorway, or a ramp within a building, must be designed for AS/NZS 1170.1 loading, have a gradient not steeper than 1:8, and be provided with landings complying with 11.2.5 at the top and bottom and at intervals not greater than 15 m.
Checked against NCC 2022 on 2026-08-31
This is the HOUSING provision, which is what applies to a Class 1a house. It is NOT the accessible-ramp rule: ramps in buildings required to be accessible are governed by AS 1428.1 via NCC Volume One, and that standard is stricter. This calculator defaults to 1:14, which is tighter than 1:8 - deliberately kept, but confirm which rule applies to your building class.
NCC Housing Provisions · 11.2.5(1)(b)
A landing associated with a ramp must have a gradient not steeper than 1:50.
Checked against NCC 2022 on 2026-08-31
This calculator sizes the ramp run only. It does not check landings, handrails or run-length limits - confirm those separately.
NSW is currently under NCC 2022. Adoption dates differ by state and territory — check yours before relying on any figure.
We cite the clause and link to the publisher so you can read the source yourself. We do not reproduce the text or tables of the NCC or of any Australian Standard.