Concrete Depot
Concrete Calculators & Tools

Patio Concrete Calculator

Estimate concrete for a patio slab by shape, thickness, waste, bags, and cost. Build a clean report with a live measurement diagram.

Measurement inputs

Live calculation
Used in the saved report.
Results show both US and metric volumes.
Choose the layout that matches the patio.
Use 1 for a single patio. Enter a section count greater than 0.
Example: 20 ft. Enter a length greater than 0.
Example: 12 ft. Enter a width greater than 0.
Use this if you already know the patio area. Enter an area greater than 0.
Diameter is the full width across the circle. Enter a diameter greater than 0.
4 in is common for many patios. Enter a thickness greater than 0.
5% simple, 10% normal, 15% complex. Waste cannot be negative.
Optional. Leave blank if you only need volume. Cost cannot be negative.
All 40, 60, and 80 lb results are still shown.
Use waste volume when ordering material.
Enter how many cubic feet one bag yields. Enter a custom yield greater than 0.
Enter valid measurements to calculate the patio concrete.

Result dashboard

Rounded estimates
Order quantity with waste
Includes 10% waste. Base slab volume is calculated from the selected patio shape.
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This calculator gives an estimate. Confirm final quantity with your contractor, engineer, or ready-mix supplier before ordering.

Formula used

Shown in report
Volume = Length × Width × Thickness × Sections

All measurements are converted to feet before calculation.