Stair Stringer Cut Calculator

Calculate stringer plumb cut and level cut angles from riser and going dimensions.

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

Riser used in calculation (kept within 115-190mm): 178mm
Going used in calculation (kept within 240-355mm): 250mm
Stringer pitch angle: 35.45deg
Plumb cut angle (from vertical): 35.45deg
Level cut angle (from horizontal): 54.55deg
Step diagonal (per step): 306.89mm

NCC Housing Provisions Table 11.2.2a (verified 2026-08-20 against both the NCC 2022 and NCC 2025 editions on ncc.abcb.gov.au - identical figures in both). NCC 2022 remains the legally operative edition in most states/territories until each jurisdiction adopts NCC 2025 on its own timeline (e.g. NSW and QLD both adopt 1 May 2027) - confirm which edition currently applies where you're building, and check for any state-specific variation, before relying on this.

What this is based on

NCC Housing Provisions · Table 11.2.2a
Sets the permitted riser and going dimensions for stairs other than spiral - the same limits this calculator clamps its riser and going inputs to before deriving the cut angles.
Checked against NCC 2022 and NCC 2025 on 2026-08-20 — figures identical in both, so this applies whichever edition your state is under.
Cut angles are geometry, not a code requirement - the NCC limits here govern the riser and going the angles are derived from.
Read the 2022 clause →Read the 2025 clause →

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.