Compare · Stair Calculator
Two independent scenarios side by side.
Scenario A
Stair stringer
Number of steps
15
Riser height
7.20 in
Within IRC residential range (6–7¾ in)
Tread depth
10.60 in
2R + T = 25 rule · IRC requires ≥ 10 in
Stringer length
183.54 in
15.29 ft · slope 36°
Scenario B
Stair stringer
Number of steps
15
Riser height
7.20 in
Within IRC residential range (6–7¾ in)
Tread depth
10.60 in
2R + T = 25 rule · IRC requires ≥ 10 in
Stringer length
183.54 in
15.29 ft · slope 36°