What does this tool do?
Stair concrete is often estimated as half the enclosing block for each step, plus a waste allowance. This calculator turns step count, rise, tread and width into cubic feet, cubic yards and bags of ready-mix.
The Formula
Volume (ft³) = Width × Steps × (Rise ÷ 12) × (Tread ÷ 12) ÷ 2 × 1.10Frequently Asked Questions
How much concrete does a flight of stairs need?
A typical 12-step flight about 3.5 ft wide uses roughly half a cubic yard. The exact figure depends on rise, tread and whether the stairs sit on fill or are self-supporting.
How do I add a landing?
Calculate the landing as length × width × thickness, add it to the stair volume, then apply the same 10% waste allowance.