How Much Concrete for Steps? Cubic Yards and Bags

How much concrete for steps? Three solid steps 4 feet wide, each 7 inches high with an 11-inch tread, take about 12.8 cubic feet of concrete, or roughly 0.48 cubic yards. That is about 22 bags of 80-pound mix before extra, or 24 with 10 percent added. More steps add up quickly, because each step sits on top of the ones below it.

Concrete calculator (steps) →

The stair formula

Treat solid steps as stacked blocks. The bottom step is one block deep, the second is two blocks deep, and so on. For n steps:

Volume (ft³) = width × rise × run × n × (n + 1) ÷ 2, with rise and run converted to feet (inches ÷ 12).

For 3 steps that are 4 feet wide with a 7-inch rise and 11-inch run: 4 × 0.583 × 0.917 × 6 = 12.8 cubic feet.

Concrete for 2 to 5 steps

All rows assume 4-foot-wide steps, a 7-inch rise and an 11-inch run, solid to the ground. Bags use Quikrete's 0.60 cubic foot yield per 80-pound bag (data sheet).

Steps	Cubic feet	Cubic yards	Yards + 10%	80 lb bags + 10%
2	6.4	0.24	0.26	12
3	12.8	0.48	0.52	24
4	21.4	0.79	0.87	40
5	32.1	1.19	1.31	59

Add a landing if you have one

A top landing is a slab at the full stair height. Volume = landing width × landing depth × total height. A 4 × 4 foot landing at the top of three 7-inch steps (21 inches, or 1.75 feet) is 28 cubic feet, more than twice the steps themselves. Some builders fill large landings with compacted stone or rubble under a thinner concrete cap to save concrete; follow your plans and local code on that.

Rise and run

Many U.S. jurisdictions use the International Residential Code, which limits risers to 7¾ inches and requires treads of at least 10 inches for residential stairs. Local amendments vary, so confirm with your building department, especially for steps at an entry door. Uniform steps matter more than the exact numbers; uneven risers are a trip hazard.

Bags or ready-mix?

Two or three steps are a manageable bag job with a mixer and a helper. Once steps plus a landing approach a yard, ready-mix or a mixing trailer is usually easier, and a single continuous pour avoids weak joints between batches. See how many bags of concrete in a yard.

Before you pour

Build sturdy forms; wet concrete pushes hard on the riser boards.
Plan footings or a base as your local code requires, and any reinforcement your plans call for.
Give the treads a slight slope so water runs off.

Try your own numbers in the concrete calculator: tap Steps and enter the count, width, rise and run.

Questions people ask

How much concrete do I need for 3 steps?

Three solid steps 4 feet wide with a 7-inch rise and 11-inch run take about 12.8 cubic feet, roughly 0.48 cubic yards, or about 24 bags of 80-pound mix with 10 percent extra.

How do you calculate concrete for stairs?

Multiply width by rise by run (in feet) by n times n plus one, divided by two, where n is the number of steps. Add any landing as a separate block.

How many bags of concrete for 4 steps?

About 40 bags of 80-pound mix with 10 percent extra for 4-foot-wide steps with a 7-inch rise and 11-inch run.

What is the maximum step height for stairs?

The International Residential Code limits risers to 7¾ inches with treads at least 10 inches, but local codes can differ.

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