5-Step Stair Stringer: Dimensions, Length & Cut Angle
Five steps covers the most common residential deck height band — a 36-inch deck lands squarely here. Every row is computed by the same engine as our interactive calculator.
5-step stringer dimensions · 10.5" tread
| Total Rise | Rise per Step | Total Run | Stringer Length | Cut Angle |
|---|---|---|---|---|
| 32" (2' 8") | 6.40" (6 3/8") | 42" | 52.8" (52 13/16") | 31.4° |
| 33" (2' 9") | 6.60" (6 9/16") | 42" | 53.4" (53 7/16") | 32.2° |
| 34" (2' 10") | 6.80" (6 3/4") | 42" | 54.0" (54 1/16") | 32.9° |
| 35" (2' 11") | 7.00" (7") | 42" | 54.7" (54 11/16") | 33.7° |
| 36" (3') | 7.20" (7 3/16") | 42" | 55.3" (55 5/16") | 34.4° |
| 37" (3' 1") | 7.40" (7 3/8") | 42" | 56.0" (56") | 35.2° |
| 38" (3' 2") | 7.60" (7 9/16") | 42" | 56.6" (56 5/8") | 35.9° |
Total run is fixed at 42" for 5 steps with a 10.5" tread: (steps − 1) × tread, because the upper floor or deck acts as the top step. For a different tread depth, total run = 4 × tread.
Rise per step is floored to the nearest 1/16" for framing-square layout. Different total rise? Use the interactive stringer calculator.
When do you need 5 steps?
Five steps covers the most common residential deck height band — a 36-inch deck lands squarely here.
A 5-step stringer covers total rises from 32" (2' 8") to 38" (3' 2") while keeping every riser at or under the IRC maximum of 7¾" (R311.7.5.1). Below 32", use a 4-step stringer; above 38", move to 6 steps.
What board do you need?
The longest stringer in the table is 56.6", so a 8-foot 2×12 covers every case with layout margin. Use solid, straight-grained 2×12 stock — after notching, the remaining "throat" must keep at least 3.5" of material for structural integrity.
Code checkpoints for a 5-step stair
- Handrail required. 5 risers is at or over the 4-riser threshold — a graspable handrail is required on at least one side (IRC R311.7.8).
- Guards required. Every total rise in the 5-step range exceeds 30", so open sides of the walking surface need 36" guards (IRC R312.1.1–.2) — see the baluster spacing calculator.
- Riser uniformity: the largest and smallest riser may differ by no more than 3/8" (IRC R311.7.5.1) — divide total rise by 5 and mark every notch from the same reference edge.
- Drop the bottom riser by one tread thickness so the first step matches the rest after treads go on.