Stair Riser Calculator
Calculate stair riser height, tread depth, stringer length, and verify building code compliance.
Stair Dimensions
Floor to floor height (typical story: 96-120 inches)
Horizontal distance available for stairs
Code Compliance
Compliant
15 risers, 14 treads
Riser Height
7-3/16"
7.200" exactly
Tread Depth
10-5/16"
10.286" exactly
Stair Geometry
Stair Angle36.9 degrees
Stringer Length15.00 ft
2R + T Rule24.69" (Good)
Materials Needed
Stringers (2x12)4 required
Tread Board Feet52.5 bf
Riser Board Feet33.8 bf
Stringer Board Feet60.0 bf
Nosing42.0 linear ft
Building Code Reference
Residential (IRC)
Max riser: 7-3/4", Min tread: 10", Min width: 36"
Commercial/IBC
Max riser: 7", Min tread: 11", Min width: 44"