🧱 Concrete Volume Calculator
Enter the shape and dimensions of a slab, footing, or column to estimate the concrete volume in cubic feet, cubic yards, and cubic metres, plus a 10% waste figure for ordering ready-mix.
🧱 Estimate Your Concrete Volume
What is a Concrete Volume Calculator?
A concrete volume calculator turns the dimensions of a pour into the numbers a supplier actually needs: how much concrete the form holds in cubic feet, the cubic yards you order ready-mix by, and the cubic metres used on metric jobsites — all from a single set of measurements.
Choose a slab, footing, or circular column, enter the dimensions, and set a quantity for repeated pours. The tool also adds a 10% waste allowance so you order enough. These are estimates for planning; verify with a structural engineer for load-bearing work.
❓ Frequently Asked Questions
How do I calculate concrete volume for a slab?
Multiply length by width by thickness in the same units. For a slab measured in feet with thickness in inches, the calculator converts thickness to feet (inches ÷ 12), so a 10 ft × 10 ft × 4 in slab is 10 × 10 × 0.333 = 33.3 cubic feet, or about 1.23 cubic yards. Ready-mix is sold by the cubic yard, so that conversion is what you order against.
Why does the calculator add 10% waste?
Real pours never match the math exactly: subgrade is uneven, forms bow, some concrete sticks to the chute and spills, and a slab poured a little thick eats extra volume. A 10% allowance keeps you from running short mid-pour, which is far more costly than a small surplus. For large or critical pours, talk to your supplier about the right buffer.
How is the volume of a round column calculated?
A column is a cylinder, so volume is π × radius² × height. The calculator takes diameter in inches, converts it to a radius in feet (diameter ÷ 2 ÷ 12), and multiplies by the height in feet. A 12-inch-diameter column 10 ft tall holds about 7.85 cubic feet of concrete.
Are these concrete volume numbers exact?
They are estimates for planning; verify with a structural engineer for load-bearing work. The geometry is exact, but real-world thickness varies and slab depth often differs from the nominal dimension. Use the figures to order, and round up to the supplier's minimum truck quantity where it applies.