Concrete Stairs Calculator

The Concrete Stairs Calculator computes concrete stairs from the relation cubic feet = number of steps x (number of steps + 1) / 2 x (rise in / 12) x (run in / 12) x width ft. It takes 4 inputs (number of steps, step rise height in inches, step run depth in inches, stair width in feet) and returns the concrete stairs. Because this is a pure mathematical or physical formula rather than a jurisdiction-specific rule, the result never changes over time: the same inputs always produce the same answer, so you can rely on it whether you are checking homework, sizing a design, or sanity-checking another tool. Enter your values in the fields below and the result updates instantly; you can also share a permalink that pre-fills the exact calculation, which is useful for teaching, reports, or collaboration. For example, with number of steps = 3, step rise height = 6 inches, step run depth = 12 inches, stair width = 4 feet, the concrete stairs works out to 12, and the worked example further down the page shows every step so you can follow the arithmetic and reproduce it by hand. The method is the standard form documented by CalculatorHub methodology, and the figure above each result carries the date it was last verified. This tool is general information and is not a substitute for professional engineering, medical, financial, or scientific advice; always check critical results against the primary source and your own judgement.

With Number of steps = 3, Step rise height = 6 inches, Step run depth = 12 inches, Stair width = 4 feet, the result is 12.

Formula: cubic feet = number of steps x (number of steps + 1) / 2 x (rise in / 12) x (run in / 12) x width ft. Source: CalculatorHub methodology, as at 2026-06-23.

Concrete Stairs12

Applies to: any numeric inputs. Method source: CalculatorHub methodology, checked 2026-06-23.

The formula

cubic feet = number of steps x (number of steps + 1) / 2 x (rise in / 12) x (run in / 12) x width ft

Worked example

With Number of steps = 3, Step rise height = 6 inches, Step run depth = 12 inches, Stair width = 4 feet:

  1. stacked step count = n x (n+1)/2 = 6.00
  2. volume cubic feet = stacks x rise/12 x run/12 x width = 12.000
  3. Concrete Stairs = 12

This worked example is one of the automated golden-value tests this calculator must pass before it can publish.

What this assumes

  • Inputs are real numbers in the units shown.
  • The result is the exact value of cubic feet = number of steps x (number of steps + 1) / 2 x (rise in / 12) x (run in / 12) x width ft; general information, not professional advice.

Frequently asked questions

What formula does this use?

cubic feet = number of steps x (number of steps + 1) / 2 x (rise in / 12) x (run in / 12) x width ft, the standard form documented by CalculatorHub methodology.

Does the result ever change over time?

No. This is a pure formula with no external rate, so the same inputs always give the same result.

Official sources and verification

Reviewed by the CalculatorHub team, edited by James Graham, 2026-06-23. See our methodology. General information, not professional advice.