How do you calculate concrete for steps?

Treat the stairs as a stack of rectangular blocks. For each step level, multiply width by tread depth by height, add the blocks together, then convert cubic inches to cubic feet or cubic yards. This calculator uses that stepped-block method and adds optional landing volume and waste.

How many bags of concrete do I need for steps?

After calculating total cubic feet, divide by the yield per bag and round up. A common 80 lb bag yields about 0.6 cubic feet, a 60 lb bag yields about 0.45 cubic feet, and a 50 lb bag yields about 0.375 cubic feet.

Should I order extra concrete for poured steps?

Yes. Many small projects use 5% to 15% extra for spillage, uneven subgrade, forms, and measurement error. Complex steps or rough excavation may need more.

Concrete project calculator

Concrete Step Calculator

Estimate concrete for poured steps before you buy bags or order ready-mix. Enter the step width, number of risers, rise, tread depth, optional landing, and waste allowance.

Concrete needed1.38 cu yd63 bags of 80 lb concrete with 10% waste.

Step dimensions

Step width (inches)Measure left to right across the steps. Number of risersA 3-riser stair has 3 vertical lifts. Riser height (inches)

Tread depth (inches) Top landing depth (inches)Use 0 if there is no poured landing. Waste allowance (%)

Concrete bags and cost

Bag size Price per bag ($) Ready-mix price per cu yd ($)

Bag yields vary by product. Check the label on the concrete mix you plan to use.

How this concrete step calculator works

The calculator treats poured stairs as stacked rectangular blocks. A three-riser stair has one block at one riser high, a second block at two risers high, and a third block at three risers high. It adds those blocks, includes the optional landing, then applies your waste allowance.

Use the result for early planning and shopping. Before pouring, confirm form dimensions, sub-base depth, reinforcement, slope, landing size, handrail requirements, and local code.

Quick examples

Small 2-step stoop: 36 in wide, two 7 in risers, 11 in treads, no landing.
Porch steps with landing: 48 in wide, three 7 in risers, 11 in treads, plus a 36 in landing.
Wide entry steps: 60 in wide, four risers, 12 in treads, and a deeper landing.

Concrete step FAQ

Does this include gravel base or forms?

No. The concrete result is only the poured concrete volume for the steps and optional landing. Add separate material for gravel base, form boards, stakes, reinforcement, and finishing supplies.

Are concrete steps solid all the way through?

Small poured steps are often calculated as solid stepped blocks for estimating. Larger stairs may be formed differently or built over compacted fill, which changes concrete volume.

Is bagged concrete or ready-mix better for steps?

Bagged concrete can work for small stoops, but the weight adds up quickly. For larger entries, ready-mix may be easier and more consistent even if there is a delivery minimum.