10-Step Stair Stringer: Dimensions, Length & Cut Angle
Ten steps is half-story territory — walk-out basements and interior flights to a landing. Every row is computed by the same engine as our interactive calculator.
10-step stringer dimensions · 10.5" tread
| Total Rise | Rise per Step | Total Run | Stringer Length | Cut Angle |
|---|---|---|---|---|
| 70" (5' 10") | 7.00" (7") | 94.5" | 117.6" (117 5/8") | 33.7° |
| 71" (5' 11") | 7.10" (7 1/16") | 94.5" | 118.2" (118 3/16") | 34.1° |
| 72" (6') | 7.20" (7 3/16") | 94.5" | 118.8" (118 13/16") | 34.4° |
| 73" (6' 1") | 7.30" (7 1/4") | 94.5" | 119.4" (119 7/16") | 34.8° |
| 74" (6' 2") | 7.40" (7 3/8") | 94.5" | 120.0" (120") | 35.2° |
| 75" (6' 3") | 7.50" (7 1/2") | 94.5" | 120.6" (120 5/8") | 35.5° |
| 76" (6' 4") | 7.60" (7 9/16") | 94.5" | 121.3" (121 1/4") | 35.9° |
| 77" (6' 5") | 7.70" (7 11/16") | 94.5" | 121.9" (121 7/8") | 36.3° |
Total run is fixed at 94.5" for 10 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 = 9 × 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 10 steps?
Ten steps is half-story territory — walk-out basements and interior flights to a landing.
A 10-step stringer covers total rises from 70" (5' 10") to 77" (6' 5") while keeping every riser at or under the IRC maximum of 7¾" (R311.7.5.1). Below 70", use a 9-step stringer; above 77", move to 11 steps.
What board do you need?
The longest stringer in the table is 121.9", so a 12-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 10-step stair
- Handrail required. 10 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 10-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 10 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.