Three solid concrete steps 4 feet wide, each rising 7 inches with 11 inch treads and a 36 inch landing at the top, take 27.4 cubic feet of concrete. With a 10% allowance that is 30.2 cubic feet, 1.12 cubic yards: 51 bags of 80 lb mix, or a small ready-mix order. Drop the landing and the same three steps need only 12.8 cubic feet, because the landing is the deepest block of the set.
How concrete for steps is calculated
Look at the steps from the side. Each step is a block that reaches from the ground to its own tread: the first is one rise tall, the second two, the third three. Each is one run deep, except the top one, which is as deep as the landing when there is one. Add the blocks' side areas, then multiply by the width.
Volume = width × rise × (1 × run + 2 × run + … + n × top depth)
For the example, in inches: 7 × (1 × 11 + 2 × 11 + 3 × 36) = 7 × 141 = 987 square inches of side profile. Times 48 inches of width is 47,376 cubic inches, ÷ 1,728 = 27.42 cubic feet. Plus 10%: 30.16 cubic feet, 1.12 cubic yards, and 30.16 ÷ 0.60 = 50.3, so 51 bags of 80 lb at Quikrete's yield.
The drawing shows the same profile to scale, with the rise, the tread, the landing and the total height marked.
Concrete calculator for steps with a landing
The landing at the top is entered as the "Landing or platform depth". It replaces the top tread, so three steps with a landing have two treads and one landing, and the landing sits at the full height. Enter 0 for steps with no landing, such as steps down a garden slope.
The 2024 International Residential Code requires a landing on each side of an exterior door, at least as wide as the door and at least 36 inches deep in the direction of travel (R318.3). The exterior landing may sit up to 7¾ inches below the threshold if the door does not swing over it (R318.3.1). That is why the landing is usually the biggest part of the pour.
Rise and run: the code check
The calculator checks each step against the IRC:
| Dimension | Limit | Section |
|---|---|---|
| Riser height | 7¾ in max | R318.7.5.1 |
| Tread depth | 10 in min | R318.7.5.2 |
| Variation within a flight | ⅜ in max between largest and smallest | R318.7.5.1 and .2 |
| Landing at a door | 36 in min, direction of travel | R318.3 |
To split a total height into equal risers, divide the height by 7¾ and round up to get the number of steps, then divide the height by that number for the rise. The stair calculator does this for any stair and shows the stringer, and the stair landing calculator sizes landings.
Solid steps or a formed shell
This calculator assumes solid steps sitting on compacted ground. If your plans call for a filled core with a concrete shell around it, the shell uses less concrete: to estimate it, subtract the fill as a smaller set of steps, or treat the treads and risers as slabs in the concrete calculator.
Width and bags
Width multiplies everything: the same three steps 6 ft wide need half again as much concrete as at 4 ft. Steps are small pours, so bags are common: 51 bags of 80 lb mix is about 4,080 lb to carry. Compare sizes in the concrete bag calculator, or tie the steps together with a few bars using the rebar calculator.
Next steps
Price the pour in the concrete cost calculator. If the steps lead down from a deck, the stair calculator works out the wooden stair above the landing.