Stair Rise Calc
Answer One flight, cut as a single stringer.

13-step stair stringer

Total rise it covers 52into100in
Risers
13
Typical total rise
91in91.000 in7 ft 7 in
Board length
15ft
The stringer board as it lies for marking, with 13 notches cut along its top edge from a 15-foot board. One notch is dimensioned 7.000 inches on the rise and 11.00 inches on the run, the waste is hatched, and the bottom cut is dropped 1.00 inches. Rise mark7 in Run mark11 in Bottom cut1 in Board15 ft
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
77in 515/16in 131/8in 1577/8in 1755/8in 1879/16in 17ft Within
78in 6in 13in 156in 1747/16in 1861/8in 17ft Within
79in 61/16in 127/8in 1541/8in 1733/16in 1843/4in 16ft Within
80in 61/8in 1211/16in 1525/16in 1721/16in 1833/8in 16ft Within
81in 61/4in 129/16in 1507/16in 1707/8in 182in 16ft Within
82in 65/16in 123/8in 1485/8in 1693/4in 18011/16in 16ft Within
83in 63/8in 121/4in 1463/4in 1685/8in 1793/8in 16ft Within
84in 67/16in 121/16in 14415/16in 1671/2in 1781/16in 16ft Within
85in 69/16in 1115/16in 1431/16in 1667/16in 1763/4in 16ft Within
86in 65/8in 113/4in 1411/4in 1653/8in 1751/2in 16ft Within
87in 611/16in 115/8in 1393/8in 1645/16in 1741/4in 16ft Within
88in 63/4in 117/16in 1379/16in 1635/16in 1731/16in 15ft Within
89in 67/8in 115/16in 13511/16in 1621/4in 17113/16in 15ft Within
90in 615/16in 111/8in 1337/8in 1615/16in 17011/16in 15ft Within
91in 7in 11in 132in 1605/16in 1691/2in 15ft Within
92in 71/16in 107/8in 1301/8in 1593/8in 1683/8in 15ft Within
93in 71/8in 1011/16in 1285/16in 1587/16in 1671/4in 15ft Within
94in 71/4in 109/16in 1267/16in 1579/16in 1661/8in 15ft Within
95in 75/16in 103/8in 1245/8in 15611/16in 1651/16in 15ft Within
96in 73/8in 101/4in 1223/4in 1557/8in 164in 15ft Within
97in 77/16in 101/16in 12015/16in 155in 163in 15ft Within
98in 79/16in 10in 120in 15415/16in 16213/16in 15ft Within
99in 75/8in 10in 120in 1559/16in 1633/8in 15ft Within
100in 711/16in 10in 120in 1563/16in 164in 15ft Within
Solution

Every dimension of this flight

Worked at a total rise of 91.00 inches.
DimensionValue
Typical total rise 91in91.00 in7 ft 7 in
Risers 13
Riser height 7in7.000 in
Treads 12
Tread run 11in11.000 in
Total run 132in132.000 in11 ft
One step along the edge 131/16in13.038 in
Marked length 1691/2in169.499 in14 ft 1.50 in
Stringer length 1605/16in160.328 in13 ft 4.33 in
Board length 15ft
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
1691/2in169.499 in14 ft 1.50 in
Bottom cut deduction
1in
  1. 7in×11in 131/16inFrom the foot
  2. 7in×11in 261/16inFrom the foot
  3. 7in×11in 391/8inFrom the foot
  4. 7in×11in 521/8inFrom the foot
  5. 7in×11in 653/16inFrom the foot
  6. 7in×11in 781/4inFrom the foot
  7. 7in×11in 911/4inFrom the foot
  8. 7in×11in 1045/16inFrom the foot
  9. 7in×11in 1173/8inFrom the foot
  10. 7in×11in 1303/8inFrom the foot
  11. 7in×11in 1437/16inFrom the foot
  12. 7in×11in 1567/16inFrom the foot
  13. 7in×11in 1691/2inFrom the foot
Code

Each figure against the limit it has to meet

Dimension Limit Code Result
Riser height, maximum 73/4in 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 11/2in ADA 2010504.5 Within
Asked about this

Questions people search for

How high will a 13-step stringer go?
A 13-step stringer covers 52 to 100 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 13-step stringer?
At a 91 inch total rise the marks run 169.499 inches along the edge of the board, so the shortest board that takes them with the top and bottom cuts is 15 feet.
How do you lay out a 13-step stringer?
Set a framing square to 7.000 inches on the tongue and 11.00 inches on the blade and step it 13 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

Building codes are adopted and amended locally. Confirm every figure with the code your jurisdiction has adopted before you cut.

Updated September 2026