How to Estimate Concrete Stairs With a Landing

Confirm the stair shape

The solid-steps calculator represents equal tread depths and riser heights that extend down to a flat base. It does not include a landing or a stair built as an inclined slab with a sloping underside. Check the project drawings before choosing a calculation method.

This guide uses dimensions already specified for the project. It does not choose stair dimensions, construction details, or structural requirements.

Estimate the repeated step flight

For a flight that matches the calculator's assumptions, enter the full width, one tread depth, one riser height, and the number of equal steps. The model adds the solid rectangular layers beneath the treads. Review the result before adding any separate part of the stair.

Measure the landing separately

If the landing is a uniform rectangular slab, use its own length, width, and specified thickness with the slab and rectangular volume calculator. Measure only the concrete volume in the landing, and split the boundary where the landing meets the stair flight so the same concrete is not included in both results.

Add the nonoverlapping volumes

For an arithmetic example, three equal solid steps that are 4 ft wide, with a 1 ft tread and a 0.5 ft rise, contain 4 × 1 × 0.5 × 3 × (3 + 1) ÷ 2 = 12 ft³ under the step model. A separate 4 ft by 4 ft landing with an illustrative 0.5 ft thickness contains 4 × 4 × 0.5 = 8 ft³. The combined measured volume is 12 + 8 = 20 ft³. The example dimensions are not a design recommendation.

If the stair shape, landing, or connection does not match these models, do not force the measurements into them. Use the project details and an appropriate estimating method.