Concrete steps calculator
Estimate a solid stepped pour, with an optional rectangular base underneath.
Calculating example…
Estimates only · see assumptions below
Your material estimate
Example estimate— yd³
- Cubic feet
- —
- Cubic meters
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Shape assumption. Solid stair profile, n full treads and n risers. Full run = n × tread depth; total height = n × rise plus base. Base spans the entire run. No hollow infill, landing, side wall or nosing.
Or use premix bags
Choose one row. Whole bags rounded up after waste.
| Bag size | Typical yield | Bags |
|---|---|---|
| 80 lb | 0.60 ft³ | — |
| 60 lb | 0.45 ft³ | — |
| 40 lb | 0.30 ft³ | — |
Typical values; use the yield on the bag label. These are concrete premix bags, not plain cement.
Volume × your $/yd³. Excludes tax, delivery, short-load fees, labor and equipment. Truck capacity and minimum orders vary.
Enter positive dimensions to see a material estimate.
Estimates only. Displayed volumes use 3 decimals; calculations and bag rounding use unrounded values. Confirm supplier increments before ordering. Not construction, commercial or tax advice.
How to calculate
- Measure the shape shown above. Use the unit labels beside each field.
- Choose a waste allowance from 0–30%. The example starts at 10%.
- Read the waste-adjusted volume or choose one bag size. Add a material price if you have a quote.
- Copy or print the estimate, then verify the mix yield and order increments with your supplier.
The formula
For n equal treads: stepped volume = width × tread depth × riser height × n(n + 1) ÷ 2. Base volume = width × (n × tread depth) × base thickness. Add the two, with every length converted to feet.
Waste-adjusted volume = measured volume × (1 + waste percent ÷ 100). One cubic foot is 0.028316846592 cubic meters. Bag counts round up once; displayed volumes round to three decimals.
Worked example
3 treads × 12 in, 6 in rise, 4 ft wide, 4 in base: stepped strips = 4 × 1 × (0.5 + 1 + 1.5) = 12 ft³. Base = 4 × 3 × ⅓ = 4 ft³. Total 16 ft³. With 10% waste: 0.651852 yd³ and 30 typical 80 lb bags.
Ready-mix material cost = waste-adjusted cubic yards × your price per cubic yard. A bag cost, when entered, is whole bags × price per bag. Neither cost includes delivery, tax, short-load fees, labor or equipment.
Geometry estimates material only. It does not select concrete strength, reinforcement, dimensions or a construction method.
Frequently asked questions
Does this assume solid or hollow stairs?
Solid. Every strip beneath each tread is concrete. Stairs on compacted fill or hollow forms use less concrete and need a different model.
How are the treads counted?
Count the full horizontal treads included in the pour. This model uses the same number of risers, with total run equal to count × tread depth. It does not add a top landing.
What does base thickness mean?
An extra rectangular layer below all treads for the full stair run. Set it to 0 if there is no separate base. Do not enter a base already included in your rise measurements.
Why not multiply full height by full run?
That would calculate a rectangular block and overcount the empty space above the treads. This tool adds strip heights of one rise, two rises, and so on.
Can I include a landing?
Calculate the landing as a rectangular slab separately. This tool does not include one automatically.
Are these safe stair dimensions?
The example is for arithmetic only. This calculator does not check building codes, fall protection, reinforcement or structural safety.