6-Step Stair Stringer: Dimensions, Length & Cut Angle
Six steps serves tall decks and split-level entries in the 40-to-46-inch range. Every row is computed by the same engine as our interactive calculator.
6-step stringer dimensions · 10.5" tread
| Total Rise | Rise per Step | Total Run | Stringer Length | Cut Angle |
|---|---|---|---|---|
| 39" (3' 3") | 6.50" (6 1/2") | 52.5" | 65.4" (65 3/8") | 31.8° |
| 40" (3' 4") | 6.67" (6 5/8") | 52.5" | 66.0" (66") | 32.4° |
| 41" (3' 5") | 6.83" (6 13/16") | 52.5" | 66.6" (66 5/8") | 33.1° |
| 42" (3' 6") | 7.00" (7") | 52.5" | 67.2" (67 1/4") | 33.7° |
| 43" (3' 7") | 7.17" (7 1/8") | 52.5" | 67.9" (67 7/8") | 34.3° |
| 44" (3' 8") | 7.33" (7 5/16") | 52.5" | 68.5" (68 1/2") | 34.9° |
| 45" (3' 9") | 7.50" (7 1/2") | 52.5" | 69.1" (69 1/8") | 35.5° |
| 46" (3' 10") | 7.67" (7 5/8") | 52.5" | 69.8" (69 13/16") | 36.1° |
Total run is fixed at 52.5" for 6 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 = 5 × 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 6 steps?
Six steps serves tall decks and split-level entries in the 40-to-46-inch range.
A 6-step stringer covers total rises from 39" (3' 3") to 46" (3' 10") while keeping every riser at or under the IRC maximum of 7¾" (R311.7.5.1). Below 39", use a 5-step stringer; above 46", move to 7 steps.
What board do you need?
The longest stringer in the table is 69.8", 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 6-step stair
- Handrail required. 6 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 6-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 6 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.