Answer
One flight, cut as a single stringer.
15-step stair stringer
Total rise it covers
60into116in
- Risers
- 15
- Typical total rise
- 105in105.000 in8 ft 9 in
- Board length
- 17ft
Range
Every total rise this stringer covers
Pick your own total rise. Every row is cut with the same number of risers.| Total rise | Riser | Tread | Total run | Stringer | Marked | Board | Result |
|---|---|---|---|---|---|---|---|
| 93in | 63/16316in | 125/858in | 1763/838in | 1997/16716in | 2105/858in | 19ft | Within |
| 94in | 61/414in | 127/16716in | 1749/16916in | 1981/414in | 2095/16516in | 18ft | Within |
| 95in | 65/16516in | 125/16516in | 17211/161116in | 1971/16116in | 20715/161516in | 18ft | Within |
| 96in | 63/838in | 123/16316in | 17013/161316in | 19515/161516in | 2065/858in | 18ft | Within |
| 97in | 67/16716in | 121/16116in | 16815/161516in | 19413/161316in | 2053/838in | 18ft | Within |
| 98in | 69/16916in | 1115/161516in | 1671/16116in | 19311/161116in | 2041/16116in | 18ft | Within |
| 99in | 65/858in | 1113/161316in | 1653/16316in | 1929/16916in | 20213/161316in | 18ft | Within |
| 100in | 611/161116in | 1111/161116in | 1635/16516in | 1911/212in | 2019/16916in | 18ft | Within |
| 101in | 63/434in | 119/16916in | 1617/16716in | 1907/16716in | 2005/16516in | 18ft | Within |
| 102in | 613/161316in | 113/838in | 1595/858in | 1897/16716in | 1991/818in | 18ft | Within |
| 103in | 67/878in | 111/414in | 1573/434in | 1883/838in | 19715/161516in | 17ft | Within |
| 104in | 615/161516in | 111/818in | 1557/878in | 1873/838in | 1963/434in | 17ft | Within |
| 105in | 7in | 11in | 154in | 1863/838in | 1959/16916in | 17ft | Within |
| 106in | 71/16116in | 107/878in | 1521/818in | 1857/16716in | 1947/16716in | 17ft | Within |
| 107in | 71/818in | 103/434in | 1501/414in | 1841/212in | 1935/16516in | 17ft | Within |
| 108in | 73/16316in | 105/858in | 1483/838in | 1839/16916in | 1923/16316in | 17ft | Within |
| 109in | 71/414in | 107/16716in | 1469/16916in | 1825/858in | 1911/818in | 17ft | Within |
| 110in | 75/16516in | 105/16516in | 14411/161116in | 1813/434in | 1901/16116in | 17ft | Within |
| 111in | 73/838in | 103/16316in | 14213/161316in | 1807/878in | 189in | 17ft | Within |
| 112in | 77/16716in | 101/16116in | 14015/161516in | 180in | 188in | 17ft | Within |
| 113in | 79/16916in | 10in | 140in | 17915/161516in | 18713/161316in | 17ft | Within |
| 114in | 75/858in | 10in | 140in | 1809/16916in | 1883/838in | 17ft | Within |
| 115in | 711/161116in | 10in | 140in | 1813/16316in | 189in | 17ft | Within |
| 116in | 73/434in | 10in | 140in | 18113/161316in | 1895/858in | 17ft | Within |
Solution
Every dimension of this flight
Worked at a total rise of 105.00 inches.| Dimension | Value |
|---|---|
| Typical total rise | 105in105.00 in8 ft 9 in |
| Risers | 15 |
| Riser height | 7in7.000 in |
| Treads | 14 |
| Tread run | 11in11.000 in |
| Total run | 154in154.000 in12 ft 10 in |
| One step along the edge | 131/16116in13.038 in |
| Marked length | 1959/16916in195.576 in16 ft 3.58 in |
| Stringer length | 1863/838in186.389 in15 ft 6.39 in |
| Board length | 17ft |
| Angle | 32.5° |
| Bottom cut deduction | 1in1.000 in |
Cut list
The marks, bottom to top
Measured along the edge of the board from the foot, after the bottom cut.- Marked length
- 1959/16916in195.576 in16 ft 3.58 in
- Bottom cut deduction
- 1in
- 7in×11in 131/16116inFrom the foot
- 7in×11in 261/16116inFrom the foot
- 7in×11in 391/818inFrom the foot
- 7in×11in 521/818inFrom the foot
- 7in×11in 653/16316inFrom the foot
- 7in×11in 781/414inFrom the foot
- 7in×11in 911/414inFrom the foot
- 7in×11in 1045/16516inFrom the foot
- 7in×11in 1173/838inFrom the foot
- 7in×11in 1303/838inFrom the foot
- 7in×11in 1437/16716inFrom the foot
- 7in×11in 1567/16716inFrom the foot
- 7in×11in 1691/212inFrom the foot
- 7in×11in 1829/16916inFrom the foot
- 7in×11in 1959/16916inFrom the foot
Code
Each figure against the limit it has to meet
| Dimension | Limit | Code | Result |
|---|---|---|---|
| Riser height, maximum | 73/434in | IRC 2021 (residential) | Within |
| Tread depth, minimum | 10in | IRC 2021 (residential) | Within |
| Stair width, minimum | 36in | IRC 2021 (residential) | Within |
| Riser height, minimum | 4in | ADA 2010504.2 | Within |
| Riser height, maximum | 7in | ADA 2010504.2 | Within |
| Tread depth, minimum | 11in | ADA 2010504.2 | Within |
| Nosing projection, maximum | 11/212in | ADA 2010504.5 | Within |
Asked about this
Questions people search for
How high will a 15-step stringer go?
A 15-step stringer covers 60 to 116 inches of total rise, floor to floor. Below that the risers fall under the 4 inch minimum; above it they pass 7 3/4 inches.
How long a board do you need for a 15-step stringer?
At a 105 inch total rise the marks run 195.576 inches along the edge of the board, so the shortest board that takes them with the top and bottom cuts is 17 feet.
How do you lay out a 15-step stringer?
Set a framing square to 7.000 inches on the tongue and 11.00 inches on the blade and step it 15 times along the board, then drop the bottom cut by one tread thickness. Every mark is listed on this page, and the stringer layout page shows where each one goes.
Next door
Other step counts
Source
Where the limits come from
2 sources, with the date each was read
- Code limits: IRC 2021 (residential), retrieved from https://www.co.routt.co.us/DocumentCenter/View/15202 on 2026-09-18. Numeric limits only; no code text is reproduced.
- Code limits: ADA 2010, 504.2, 504.5, retrieved from https://www.access-board.gov/aba/chapter/ch05/ on 2026-09-18. Numeric limits only; no code text is reproduced.
Building codes are adopted and amended locally. Confirm every figure with the code your jurisdiction has adopted before you cut.
Updated September 2026