16-Step Stair Stringer: Dimensions, Length & Cut Angle
Sixteen steps is a long single flight for 10-foot floor-to-floor heights — check headroom and consider a landing. Every row is computed by the same engine as our interactive calculator.
16-step stringer dimensions · 10.5" tread
| Total Rise | Rise per Step | Total Run | Stringer Length | Cut Angle |
|---|---|---|---|---|
| 117" (9' 9") | 7.31" (7 5/16") | 157.5" | 196.2" (196 3/16") | 34.9° |
| 118" (9' 10") | 7.38" (7 3/8") | 157.5" | 196.8" (196 13/16") | 35.1° |
| 119" (9' 11") | 7.44" (7 7/16") | 157.5" | 197.4" (197 3/8") | 35.3° |
| 120" (10') | 7.50" (7 1/2") | 157.5" | 198.0" (198") | 35.5° |
| 121" (10' 1") | 7.56" (7 9/16") | 157.5" | 198.6" (198 5/8") | 35.8° |
| 122" (10' 2") | 7.63" (7 5/8") | 157.5" | 199.2" (199 1/4") | 36.0° |
| 123" (10' 3") | 7.69" (7 11/16") | 157.5" | 199.8" (199 13/16") | 36.2° |
Total run is fixed at 157.5" for 16 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 = 15 × 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 16 steps?
Sixteen steps is a long single flight for 10-foot floor-to-floor heights — check headroom and consider a landing.
A 16-step stringer covers total rises from 117" (9' 9") to 123" (10' 3") while keeping every riser at or under the IRC maximum of 7¾" (R311.7.5.1). Below 117", use a 15-step stringer; above 123", move to a longer flight with a landing.
What board do you need?
The longest stringer in the table is 199.8" — beyond a 16-foot 2×12. Plan a mid-flight landing (two shorter stringer runs) or order LSL stringer stock. 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 16-step stair
- Handrail required. 16 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 16-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 16 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.