Concrete Volume Calculator
Concrete for footings, walls, round columns, hollow tubes and solid stairs, in cubic yards or cubic metres, plus bags.
Your pour
Filled in with example values. Replace them with your own.
Optional
Adds a percentage on top of the measured volume.
Each bag makes a set volume of concrete, called its yield. It is printed on the bag and varies by product.
Results update as you type.
Result
Concrete needed: 0.889 yd³
You need about
0.889cubic yards
- Volume in cubic feet
- 24 ft³
- Volume in cubic metres
- 0.68 m³
- One pieceBefore any extra
- 4 ft³
- Premixed bags
- Turn on “Count premixed bags”
How it’s calculated
One piece
2 ft × 2 ft × 1 ft = 4 ft³
6 pieces
4 ft³ × 6 = 24 ft³
In cubic yards
24 ft³ ÷ 27 = 0.889 yd³
How the concrete volume calculator works
Choose the shape you are pouring: a rectangular footing, wall or pad, a round column, a hollow tube, or a flight of solid stairs. Enter its measurements in any mix of units, and how many identical pieces there are.
The calculator converts everything to the same unit, works out the volume of one piece, multiplies by the number of pieces and shows the total in cubic yards (how ready-mix concrete is ordered in the US) or cubic metres. You can add an allowance for spillage and count premixed bags from the yield printed on the bag.
The formulas
Footing, wall or pad = Length × Width × Depth
Round column = π × (Diameter ÷ 2)² × Height
Hollow tube = π ÷ 4 × (Outside² − Inside²) × Height
Solid stairs = Width × Run × Rise × n × (n + 1) ÷ 2
Total = One piece × Number of pieces × (1 + Extra % ÷ 100)
For stairs, n is the number of steps. The first step is one rise tall, the second two rises, and so on, so the flight adds up to 1 + 2 + … + n = n × (n + 1) ÷ 2 blocks of width × run × rise.
Worked examples
Footings. Six square footings, each 2 ft × 2 ft and 12 inches deep:
- One footing: 2 × 2 × 1 = 4 ft³
- Six footings: 4 × 6 = 24 ft³
- In cubic yards: 24 ÷ 27 = 0.89 yd³
Columns. Ten round columns, 12 inches across and 4 ft tall:
- Cross-section: 3.1416 × 0.5² = 0.785 ft²
- One column: 0.785 × 4 = 3.14 ft³
- Ten columns: 31.42 ft³ = 1.16 yd³
Stairs. Four steps, 7 in rise, 11 in run, 3 ft wide:
- One block: 3 × (11 ÷ 12) × (7 ÷ 12) = 1.604 ft³
- Four steps: 1.604 × (4 × 5 ÷ 2) = 16.04 ft³ (0.59 yd³)
Units, assumptions and limitations
- Conversions use exact definitions: 1 inch = 2.54 cm, 1 foot = 12 inches, 1 yard = 3 feet, 1 litre = 0.001 m³.
- Every shape is treated as having straight, even sides. Excavated footings with uneven sides usually need more concrete.
- Stairs are solid down to the ground, with no landing and no sloped underside.
- Reinforcement, formwork and a gravel base are not included.
- No bag yield is assumed. Products differ, so enter the yield from the bag you will buy.
- Sizes for footings, columns and stairs depend on the design and on local building rules. This calculator does not recommend any.
Frequently asked questions
How do I calculate a job made of different shapes?
Work out each shape separately, for example the footings, then the columns, and add the volumes together. The calculator handles one shape at a time, with as many identical pieces as you need.
What is the yield of a bag of concrete?
It is the volume of finished concrete one bag makes once mixed with water. It depends on the product and the bag weight, so it is printed on the bag, usually in cubic feet or litres. Enter that figure to count bags.
Do the stairs include a landing at the top?
No. The stairs are treated as solid steps sitting on the ground, with the top step as deep as the others. Add a landing as a separate footing, wall or pad: its length, width and depth.
What is a hollow tube used for?
It covers round shapes with a hollow core, such as a ring wall or a column poured around a pipe. Enter the outside and inside diameters; the calculator subtracts the core.
Does this include the gravel base or reinforcement?
No, only the concrete. Steel reinforcement takes up a small amount of space, which this calculator ignores. For a gravel base, use the Gravel Calculator.