Stringer layout for a 36 inch rise
Use our stair design calculator to determine the total rise and ensure compliance with the IRC riser limit of 7.75 inches. Get accurate measurements for safe and comfortable stair construction.
Formula SSC-2026.1
IRC check pass
Risers / treads
5 / 4
Riser inside 4 to 7.75 in
Exact riser
7 3/16 in
182.9 mm
Total run
3 ft 6 in
1,067 mm
Stringer length
4 ft 7 5/16 in
Order 8 ft 2x12
Incline
40.60°
Square 7 3/16 in rise · 10 1/2 in run
Stringers @ 16 in
3
Throat 5.31 in on a 2x12
Rise, run, and the incline are scaled from the live riser and tread. Framing-square gauges match the exact riser and the tread depth.
| Item | Net | Waste | Order | Unit price | Line total | Source Spec Material / Tool |
|---|---|---|---|---|---|---|
| 8 ft 2x12 | 5.21 ft cut | end cuts included | 3 boards | USD | $50.40 | Source Spec Material / Tool |
| Stringer delivery weight | 67 lb | — | 30 kg | 2.8 lb/ft planning weight | — | Source Spec Material / Tool |
Source links open a product search on the Amazon storefront for the selected currency. SiteSpecCalc may earn a commission. The link does not change the quantities above.
| Total rise | Risers | Exact riser | Treads | Run | 2x12 stock | Check |
|---|---|---|---|---|---|---|
| 3 ft 0 in | 5 | 7 3/16 in | 4 | 3 ft 6 in | 8 ft | Pass |
| 3 ft 6 in | 6 | 7 in | 5 | 4 ft 4 1/2 in | 8 ft | Pass |
Show the deterministic formula
Risers = round(total rise ÷ target rise). Exact riser = total rise ÷ risers, reported to the nearest 1/16 in and in millimeters. Treads = risers − 1. Total run = treads × tread depth.
Diagonal = hypotenuse of stringer rise and total run. A dropped header uses total rise minus landing thickness. Stock is the next 8, 10, 12, 14, 16, 18, 20, or 24 ft board.
Stringers = floor(width ÷ 16) + 1, with a minimum of 2. Throat ≈ 11.25 − (riser × tread) ÷ hypotenuse.
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Project: Stringer layout for a 36 inch rise
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This sheet is an estimate for ordering and layout discussion. It is not a sealed design. Confirm the quantities with a licensed local professional and the authority having jurisdiction before you buy or build.
Engineering notes
When designing stairs, it's essential to consider the total rise, which in this case is 36 inches. According to the International Residential Code (IRC), the maximum riser height is limited to 7.75 inches. This means that the total number of risers should be calculated to ensure that each riser does not exceed this height.
It's important to note that headroom is not calculated in this context, but ensuring adequate headroom is crucial for safety and comfort in stair design.
Code reference
IRC R311.7.5
Field questions
- What is the maximum riser height allowed by the IRC?
- The maximum riser height allowed by the IRC is 7.75 inches.
- How do I calculate the number of risers for a total rise of 36 inches?
- To calculate the number of risers, divide the total rise (36 inches) by the maximum riser height (7.75 inches). This will give you the number of risers needed to comply with the IRC.
- Is headroom considered in stair design?
- In this context, headroom is not calculated, but it is important to ensure that there is adequate headroom for safety and comfort.