Concrete Depot
Concrete Calculators & Tools
Dashboard-ready report tool

Concrete Slab Foundation Calculator

Estimate concrete for a slab foundation with slab thickness, thickened perimeter edge, optional interior beam, waste, bags, cost, and a branded report with a live 3D measurement diagram.

Measurement inputs

Live calculation updates the result, shape, formula, and report data.
Live
Used in saved report.
Switches starter units only.
Foundation footprint
Enter a length greater than 0.
Enter a width greater than 0.
Enter a slab thickness greater than 0.
Thickened perimeter edge
Set 0 if there is no thickened edge. Edge beam width cannot be negative.
Total depth from top of slab. Edge total depth cannot be negative.
Optional interior thickened beam
Use 0 if not needed. Beam length cannot be negative.
Beam width must be greater than 0 when beam length is used.
Beam total depth must be greater than 0 when beam length is used.
Waste, bags, and cost
10% is common for many jobs. Waste cannot be negative.
Optional concrete price. Cost cannot be negative.
Used only for cost estimate.
Bag counts always round up.

Live 3D foundation preview

Labels are based on your actual input values.
Length
–
Width
–
Slab thickness
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Edge total depth
–
Order quantity with waste
–
Enter valid dimensions to calculate the foundation concrete volume.
Total before waste–
Cubic feet–
Cubic meters–
Estimated cost–
Base slab volume
–
Thickened edge extra
–
60 lb bags
–
80 lb bags
–
Foundation area
–
Interior beam extra
–
Waste added
–
Bag basis
–

Formula used

The report saves this formula, the steps, and the full SVG diagram.
Total foundation volume = slab volume + thickened edge extra volume + optional interior beam extra volume.
This is an estimate. Confirm final quantity with your contractor, engineer, or concrete supplier before ordering.