Stair Rise Calc
Answer Worked out from a total rise of 96.00 inches, floor to floor.

Stringer length calculator

Marked length1811/2in181.472 in15 ft 1.47 in
Total rise
96in96.00 in8 ft
Board length
16ft
Stringer length
1721/4in
The triangle the stringer is cut from: 96.00 inches of total rise against 143.00 inches of total run, with the stringer measured at 172.235 inches along the hypotenuse. One step beside it carries the 31.9 degree slope the steps themselves stand at. Stringer length1721⁄4 in Total rise96 in Total run143 in Angle31.9 ° One step
Given

What this was worked out from

in
in
in
in
in
in

These are the figures every number on this page is worked for.

Solution

Every dimension of this flight

To the nearest sixteenth
DimensionValue
Total rise 96in96.00 in8 ft
Risers 14
Riser height 67/8in6.857 in
Treads 13
Tread run 11in11.000 in
Total run 143in143.000 in11 ft 11 in
One step along the edge 1215/16in12.962 in
Marked length 1811/2in181.472 in15 ft 1.47 in
Stringer length 1721/4in172.235 in14 ft 4.24 in
Board length 16ft
Angle 31.9°
Stringer angle 33.9°
2 risers + 1 tread 2411/16in24.71 in2 ft 0.71 in
Bottom cut deduction 1in1.000 in
Tread thickness 1in1.00 in
Nosing 1in1.00 in
Stair width 36in36.00 in3 ft
Options

The marks this length is cut to

  1. 67/8in×11in 1215/16inFrom the foot
  2. 67/8in×11in 2515/16inFrom the foot
  3. 67/8in×11in 387/8inFrom the foot
  4. 67/8in×11in 517/8inFrom the foot
  5. 67/8in×11in 6413/16inFrom the foot
  6. 67/8in×11in 773/4inFrom the foot
  7. 67/8in×11in 903/4inFrom the foot
  8. 67/8in×11in 10311/16inFrom the foot
  9. 67/8in×11in 11611/16inFrom the foot
  10. 67/8in×11in 1295/8inFrom the foot
  11. 67/8in×11in 1429/16inFrom the foot
  12. 67/8in×11in 1559/16inFrom the foot
  13. 67/8in×11in 1681/2inFrom the foot
  14. 67/8in×11in 1811/2inFrom the foot

No board depth is asserted here. Enter the depth of your own board to see the throat.

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
Calculators

Work out one part on its own

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