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

Tread depth calculator

Tread depth11in11.000 in
Total rise
96in96.00 in8 ft
Tread run
11in
Nosing
1in
Two treads in section. The run of 11.00 inches is taken nose to nose, the nosing hangs 1.00 inches past the riser below, the tread board is 12.00 inches wide and 1.00 inches thick, and the riser between them is 6.857 inches. Tread run11 in Tread board12 in Nosing1 in Tread thickness1 in Riser height67⁄8 in
Given

What this was worked out from

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

What each tread run does to the flight

Tread 2R + T Total run Result
10in 2311/16in 130in Within
101/2in 243/16in 1361/2in Within
11in 2411/16in 143in Within
111/2in 253/16in 1491/2in Within
12in 2511/16in 156in Within

Cut the tread board 12.000 in wide to leave the nosing.

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