Concrete Stairs Calculator — Volume for Solid Steps

Concrete steps poured against the ground or a foundation are solid blocks stacked like a staircase, so each step up holds more concrete than the one below it. This calculator adds them up. Enter the riser height, tread depth, width and number of steps, plus the depth of a top landing if the steps lead to a platform, and it returns the volume to order, the total rise and run, and a step-by-step breakdown.

How to use this tool

1. Choose inches or centimetres.
2. Enter the number of steps up (risers), the height of each riser and the tread depth.
3. Enter the width of the stairs.
4. If there is a landing at the top, enter its depth front to back; leave 0 when the top step is a normal tread.
5. Set the waste allowance and read the total and the per-step table.

Formula

V = W × R × [T × n(n − 1) ÷ 2 + P × n]

W is the stair width, R the riser height, T the tread depth, n the number of risers and P the depth of the top level — the landing, or one tread when there is no landing. Step k stands k × R tall, so the steps form a solid stack down to the ground. Divide cubic inches by 1,728 for cubic feet.

Example

Four steps with 7 in risers, 11 in treads and a 48 in width hold 48 × 7 × 11 × (1 + 2 + 3 + 4) = 36,960 in³, which is 21.39 ft³ or 0.79 yd³. With 10% extra, order 0.87 yd³ — or 40 bags of 80 lb premix. The steps rise 28 in and run 44 in front to back.