Concrete Calculator
Free concrete calculator for slabs, footings, pads, and common projects. Estimate cubic yards and bag quantities with ATHENA.
Plan concrete quantities before ordering and verify mix yield, delivery requirements, site conditions, and waste allowance.
Plan the project with a practical estimate
For slabs, patios, walkways, footings, and pads, use finished project measurements and verify mix yield, delivery requirements, reinforcement, site conditions, and waste allowance before ordering.
How much concrete do I need?
For a rectangular slab or pad, estimate cubic yards by multiplying length in feet × width in feet × thickness in inches, then dividing by 324.
How do I estimate concrete bags?
Start with the project volume, then compare it with the yield listed for the specific bag size you plan to buy. Bag yields vary by product, so use the manufacturer's stated yield for the final quantity.
Should I order extra concrete?
Allow for practical site conditions, uneven subgrade, measurement uncertainty, placement loss, and the supplier's recommendations. Verify the final order quantity before scheduling delivery.
Enter the requested project inputs, review the result, and compare it with actual product specifications, site conditions, scope, supplier requirements, or business rules before making a final purchase or pricing decision.
ATHENA tools are designed to make common planning calculations faster and easier to check. Use the result as a starting point and keep the final decision tied to the real project requirements.