Concrete steps are poured as a solid mass that rises from the ground in stages: the first step is one rise tall, the second is two rises, and so on up to the top. That makes the quantity of concrete grow faster than you might expect, which is why it is worth calculating before ordering. This calculator finds the volume for a set of solid steps, with an optional landing, and shows the total rise and run so you can check them against code.
How to use the concrete steps calculator
- Enter the number of steps you will climb, not counting the landing or the ground.
- Enter the rise (the height of each step) and the run (the depth of each tread).
- Enter the width of the steps.
- Add a landing depth if the stairs end on a platform, and a waste allowance.
Concrete steps formula
Landing volume = width × landing depth × (n × rise)
Cubic yards = cubic feet ÷ 27
The first step is a block rise tall, the second is two rises tall, and the nth is n rises tall. Adding them gives rise × (1 + 2 + … + n) = rise × n(n + 1) ÷ 2, and each block has the plan area width × run. The landing is as tall as the full set of steps.
Worked example: three steps, 4 ft wide, 7 in rise and 11 in run
- Sum factor: 3 × 4 ÷ 2 = 6.
- Volume: 48 × 11 × 7 × 6 = 22,176 in³ = 12.83 cu ft.
- In cubic yards: 12.83 ÷ 27 = 0.48 cu yd.
- 80 lb bags (0.60 cu ft each): 12.83 ÷ 0.6 = 21.4 → 22 bags before waste.
- Total rise is 21 in and total run is 33 in.
Concrete for steps 48 in wide (7 in rise, 11 in run, 10% waste)
| Steps | Total rise | Total run | Cubic feet (no waste) | Cubic yards with waste | 80 lb bags with waste |
|---|---|---|---|---|---|
| 1 | 7 in | 11 in | 2.14 | 0.09 | 4 |
| 2 | 14 in | 22 in | 6.42 | 0.26 | 12 |
| 3 | 21 in | 33 in | 12.83 | 0.52 | 24 |
| 4 | 28 in | 44 in | 21.39 | 0.87 | 40 |
| 5 | 35 in | 55 in | 32.08 | 1.31 | 59 |
| 6 | 42 in | 66 in | 44.92 | 1.83 | 83 |
| 8 | 56 in | 88 in | 77.00 | 3.14 | 142 |
Rise and run guidelines
- Riser height: the IRC allows a maximum of 7¾ inches for residential stairs; all risers in a flight should be nearly the same, within 3/8 inch.
- Tread depth: at least 10 inches in residential stairs under the IRC.
- Comfort rule: a common rule is that two risers plus one tread should be about 24–25 inches; 7 + 7 + 11 = 25.
- Handrails and guards are required above certain heights; check local rules.
Before you pour
Build sturdy forms and brace them, as wet concrete pushes hard on the riser boards. Place compacted gravel under the steps, and tie them into the house wall or slab with dowels if the plans call for it. Steps should be reinforced; see the Rebar Material Calculator. Because each step is a different height, many people pour them in one go and trowel the treads with a slight slope away from the house for drainage.
For other concrete work see the Concrete Calculator; for wooden stairs and stringers use the Stair Calculator, and for the foundation of a stair or wall use the Concrete Footing Calculator.
Frequently asked questions
How much concrete do I need for 3 steps?
Three solid steps 4 ft wide with a 7 inch rise and 11 inch run need 12.8 cubic feet (0.48 cubic yards) before waste, because each step is a solid block from the ground up to its own height.
What is the formula for concrete stairs?
Volume = width × run × rise × n(n + 1) ÷ 2 for n solid steps. The sum 1 + 2 + … + n counts the stacked blocks, since step k is k rises tall.
What rise and run are allowed?
The International Residential Code limits residential risers to 7¾ inches maximum and requires treads at least 10 inches deep (R311.7). Your local code may differ, and public buildings have stricter rules.
Do I need to add a landing?
A landing at the top of exterior stairs is usually required at a door. The landing is calculated as a slab as high as the total rise; enter its depth to include it.
Should the steps be solid or hollow?
Solid steps are heavy but simple. Taller stairs often use a thickened slab or a stepped slab on fill to save concrete. This calculator assumes solid steps; a thinner design needs a separate calculation.