Printable stair code requirements
The same numbers as the full chart, laid out to print on one sheet. The full chart has the sources, the tiers behind each number and the reasons.
One page on Letter or A4. To save a PDF, pick “Save as PDF” in the print dialog.
For a sheet that matches the screen, choose portrait, Letter or A4, and 100% (actual size) scale in the print dialog. Saved as a PDF, it opens on a phone or tablet in the shop with no signal. The numbers change only when the full chart’s sources do, so check the full chart now and then against the copy on your wall.
| What | The rule | IRC 2024 / 2021 |
|---|---|---|
| Riser height | 7 3/4 in (196 mm) at most, measured between the leading edges of the treads. | R318.7.5.1 / R311.7.5.1 |
| Tread depth | 10 in (254 mm) at least, nosing to nosing. | R318.7.5.2 / R311.7.5.2 |
| Same size all the way | The largest riser may exceed the smallest by 3/8 in (9.5 mm) at most in one flight; the same for treads. | R318.7.5.1–.2 / R311.7.5.1–.2 |
| Nosing | 3/4 to 1 1/4 in (19–32 mm) on solid risers; not required where treads are 11 in (279 mm) or deeper. | R318.7.5.3 / R311.7.5.3 |
| Open risers | Where the opening is more than 30 in (762 mm) above the floor or grade below, a 4 in (102 mm) ball must not pass through. | R318.7.5.1 / R311.7.5.1 |
| Headroom | 6 ft 8 in (2032 mm) at least, measured straight up from the line of the nosings. | R318.7.2 / R311.7.2 |
| Rise of one flight | 12 ft 7 in (3835 mm) at most between floors or landings; a taller stair needs a landing. | R318.7.3 / R311.7.3 |
| Width | 36 in (914 mm) clear above the handrail; 31 1/2 in (787 mm) at and below it with one handrail, 27 in (698 mm) with two. | R318.7.1 / R311.7.1 |
| Landings | A floor or landing at the top and bottom of each flight, at least as wide as the stair and 36 in (914 mm) deep on a straight run. | R318.7.6 / R311.7.6 |
| Handrail | On at least one side of every flight with four or more risers, 34 to 38 in (864–965 mm) above the nosings. | R318.7.8, R320.2 / R311.7.8 |
| Guard | On open sides more than 30 in (762 mm) above the floor or grade; at least 34 in high along a stair, measured from the nosings. | R321.1 / R312.1 |
International Residential Code 2024 and 2021 (International Code Council). Your local code, and its amendments, govern. woodworkingmath.com/carpentry/stair-code-requirements/ Version 8 Nov 2026. Free to share under CC BY 4.0: credit Woodworking Math (woodworkingmath.com).