Concrete Calculator

Rectangular: Volume (yd³) = [Length (ft) × Width (ft) × Thickness (in) ÷ 12] ÷ 27.

Cylindrical: Volume (yd³) = [π × Radius² (ft) × Depth (ft) × Quantity] ÷ 27.

The waste allowance is applied after calculating the geometric volume. For example, a 10% allowance means the estimated order quantity is the calculated volume × 1.10.

Pre-bagged concrete quantities are approximate because bag yields vary by product. This estimator uses approximately 0.60 cu ft per 80 lb bag and 0.45 cu ft per 60 lb bag. Always check the yield printed on the specific product before purchasing.

For larger pours, ready-mix delivery may be more practical than mixing individual bags. Confirm minimum delivery quantities, short-load fees, and site access with the supplier.

This is a material planning estimate, not an engineering specification. Structural concrete work should follow the plans, specifications, and requirements applicable to the project.