Calculate concrete volume and materials for slabs, cylinders, and footings
This concrete calculator helps you estimate the volume and materials needed for concrete projects. It supports three common shapes: rectangular slabs (ideal for patios, driveways, and floors), cylinders (ideal for columns and piers), and square footings (ideal for foundations and post bases).
The calculator provides volume in cubic feet, cubic yards, and cubic meters, along with the number of 40lb, 60lb, and 80lb bags of concrete needed. If you provide a price per cubic yard, it also shows an estimated material cost.
Select the shape of your project (slab, cylinder, or footing). Enter the dimensions — lengths in feet, depth in inches. Optionally enter the price per cubic yard to see estimated cost. Click Calculate to see the volume in all standard units, bag counts for different bag sizes, total weight, and estimated cost.
Approximately 90 bags of 40lb mix, 60 bags of 60lb mix, or 45 bags of 80lb mix are needed per cubic yard. These estimates assume standard concrete mix density of about 150 lb per cubic foot.
For small projects (under 2 cubic yards), bagged concrete is usually more practical. For larger projects, ready-mix delivered by truck is typically more economical and consistent. This calculator helps you estimate either way so you can compare costs.