# Maximum & Minimum Stair Riser Heights in Australia The maximum and minimum stair riser height under NCC 2025 Housing Provisions 11.2 — why every riser in a flight must match, and how to size risers from a floor-to-floor height. - Canonical HTML: https://www.chippy.tools/building-codes/au/stairs/stair-riser-heights/ - Publisher: Chippy Tools - Updated: 2026-09-06 - Market: au - Code edition / reference: NCC 2025 - References: HP 11.2 - Scope: Australia; Class 1 and 10 Housing Provisions. Confirm local adoption and variations. - Source text checked: 2026-09-06 - Review scope: Official source cross-check; not a site-specific compliance assessment. ## The requirement A riser can be no more than **190 mm** high and no less than **115 mm** (NCC 2025, clause 11.2). Every riser in a flight must also match. Those are the standard-stair limits; the uniformity requirements and exceptions in clause 11.2.2 also apply. - **Riser (R)** — the height of one step, measured from the top of one tread to the top of the next. | Riser limit (NCC 2025) | Value | |--------------------------------------|----------------------------------------------------------------------------------------------------------------------| | Maximum riser (R) | **190 mm** | | Minimum riser (R) | **115 mm** | | Variation between risers in a flight | no more than **5 mm** between adjacent risers; no more than **10 mm** between the largest and smallest in the flight | | Risers per flight before a landing | max **18** | **Diagram labels:** 2790 mm; ×15; 186 mm (R ≤ 190 mm) NCC 2025 Housing Provisions 11.2 Riser height is the first stair number people get wrong. Too tall and the climb is hard work and a hazard. Too short and your toes catch on the way up. On a normal job, the **190 mm top limit** is the one that matters. A standard floor-to-floor height rarely gets you near the 115 mm bottom limit. So the job is almost always about adding enough steps to bring each one *down* under 190 mm. The rest of the rule matters just as much: **every step in a run has to be the same height.** The rules only allow a tiny difference between steps. Your foot learns the height on the first step and expects it on every step after. One step that’s 15 mm out is a trip waiting to happen. It’s usually the top or bottom step, where someone has “fixed” a height by eye. Split the total height evenly and keep the steps the same. Step height doesn’t work alone. It’s tied to the **going** (how deep the step is) through the **2R+G** check. Two step heights plus one step depth must land inside a set range (**550–700 mm**, Table 11.2.2a). Pick your step height first, then pick a step depth that keeps 2R+G in range. The full step-height-plus-depth rule is in the [NCC stair requirements](https://www.chippy.tools/building-codes/au/stairs/ncc-stair-requirements/) article. ## Work the riser out by hand You work out the step height from the height you have to climb — the **floor-to-floor** measurement — not the other way around. Say floor-to-floor is **2790 mm**. 1. **Find the smallest number of steps.** Divide by the top step height: 2790 ÷ 190 = **14.68**. You can’t have part of a step, and rounding *down* to 14 would push each step over 190 mm, so round up to **15 risers**. 2. **Divide the height back across those steps.** 2790 ÷ 15 = **186 mm** per step. 3. **Check it against the limits.** 186 mm is under the 190 mm top limit and well over the 115 mm bottom limit — good. All 15 steps are cut at 186 mm, so they all match. Want to check it against the step depth while you’re here? With a 250 mm going: (2 × 186) + 250 = **622 mm**, well inside the 550–700 range. Two traps to watch. If you’d rounded to 14 steps, each would be 2790 ÷ 14 = **199 mm** — over the limit, and not allowed. And if your floor-to-floor is out by even 20 mm on site, your step height changes. Always measure the real height. Don’t work off the number on the plan. ## Calculate and keep your working [Download the Chippy Tools stair set-out worksheet](https://www.chippy.tools/building-codes/printables/) to record your inputs and the approved requirements. The Chippy Tools stair calculator does exactly this. Type in the floor-to-floor height. It gives you the number of steps and the height of each one. It warns you if a step is over the limit. It runs the 2R+G check too. If you want the full method behind it, see [How to calculate stairs: rise, run & number of steps](https://www.chippy.tools/building-codes/au/stairs/how-to-calculate-stairs/). ## Sources - **NCC 2025, ABCB Housing Provisions Standard, clause 11.2** — stairway riser (maximum, minimum, and consistency within a flight). Confirm each figure at [the official NCC provision](https://ncc.abcb.gov.au/editions/ncc-2025/adopted/housing-provisions/11-safe-movement-and-access/part-112-stairway-and-ramp-construction). *(Confirmed against the NCC 2025 Housing Provisions Standard, source text checked 2026-09-06.)* - Part of the [NCC for Chippies](https://www.chippy.tools/building-codes/au/ncc-for-chippies/) guide. See also the state tracker at [Building codes in Australia](https://www.chippy.tools/building-codes/au/). The step numbers are the same in NCC 2022 and 2025, but the date each state started using them is not. Still on NCC 2022? This article is written against NCC 2025. NSW and SA don't adopt NCC 2025 until 1 May 2027, and Tasmania has frozen its residential changes — so if your job is being certified under NCC 2022, confirm the requirement against that edition. Core stair and room geometry is largely unchanged between editions; where a number did change, it's called out in the article body. Content adapted from the National Construction Code 2022, provided by the Australian Building Codes Board under the CC BY 4.0 licence. This page is general information for tradespeople and is not compliance, engineering or legal advice. Requirements are subject to state and territory variations and adoption timing. Always confirm requirements with your building certifier and relevant state authority. ## Frequently asked questions ### What is the maximum riser height for stairs in Australia? For steps in a house or garage (Class 1 and 10), the riser (R) can be no more than 190 mm. That's the top height for one step. Go higher and the step is too tall to climb safely. The fix is to add another step, which brings each one back down under 190 mm. ### What is the minimum stair riser height under the NCC? The rules also set a smallest step height. The figure is 115 mm. Steps any shorter and your toes can catch on the way up. On a normal floor-to-floor height you almost never get this low. The 190 mm top limit is the one you have to watch. ### Do all the risers in a flight have to be the same height? Clause 11.2.2 permits up to 5 mm between adjacent risers and up to 10 mm between the largest and smallest riser in a flight. Aim for equal set-out dimensions. Your foot learns the first step height and expects it again. An odd step can cause a trip. Split the total height into equal steps. ### How do I work out the riser height from a floor-to-floor measurement? Measure the height from one floor to the next. Divide it by 190 to get the smallest number of steps you can use. Round that up to a whole number. Then divide the floor-to-floor height by that number of steps. That gives you the height of each step. Check it sits between 115 mm and 190 mm. ### Does the riser interact with the going? Yes. The step height and the step depth work together. Two step heights plus one step depth (2R+G) must land inside a set range. Pick your step height first. Then pick a step depth that keeps 2R+G in range. See the main stair-requirements article for the full rule. ## Source-check references - [NCC 2025 Housing Provisions 11.2.2 and Table 11.2.2a; 11.2.5](https://ncc.abcb.gov.au/editions/ncc-2025/adopted/housing-provisions/11-safe-movement-and-access/part-112-stairway-and-ramp-construction)