Concrete Stairs Calculator
Calculate concrete volume for poured stairs. Enter total rise, stair width, and tread dimensions for cubic yards and bag counts.
๐ช Concrete Stairs Calculator
Results
Number of Steps5 steps
Actual Riser Height7.20 in
Volume13.8 cu ft
Volume0.51 cu yd
80 lb Bags23 bags
๐ก How to Calculate Concrete for Stairs
Poured concrete stairs are calculated by combining the volume of each individual step plus the underlying slab (stringer) volume. Each step is essentially a rectangular block: tread depth ร riser height ร stair width. The stringer adds a triangular cross-section beneath the steps.
Building code requirements for stairs: riser height 4โ7.75 inches (7โ7.5 inches is ideal), tread depth minimum 10โ11 inches, and stair width minimum 36 inches. The total rise determines the number of steps: divide total rise by desired riser height and round to the nearest whole number.
A 36-inch total rise with 36-inch wide stairs, 7.5" risers, 11" treads, and 6" slab: 5 steps. Volume โ 8.4 cu ft = 0.31 cu yd. That's about 14 bags of 80 lb concrete mix.