NCC 2025 Vol One D3D11, D3D22, D4D4, D4D9, D4D12 · AS 1428.1:2021
Max 1:14. Landings every 9 m at 1:14 to 15 m at 1:20 (interpolated); a walkway 15 m at 1:20 to 25 m at 1:33, none flatter. Handrails both sides when steeper than 1:20.
Enter the ratio denominator — 40 for 1:40, 0 for level.
Enter the dimensions above to evaluate compliance.