How we worked it out
Updated as you change the numbers.
- Volume = Σ (step number × riser × tread × width) + landing × total rise × width, plus waste.
Method and assumptions
Seen from the side, poured steps form a staircase of rectangles stacked from the ground; the k-th step from the top stands k risers tall. This ignores any hollow fill, which can cut concrete for tall steps.
Questions
How much concrete for 4 steps, 7 in risers, 11 in treads, 4 ft wide?
About 0.87 cubic yards with 10% extra, or 40 bags of 80 lb.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.