Concrete Depot
Concrete Calculators & Tools

Concrete Floor Calculator

Estimate concrete volume, floor area, waste, bag counts, and cost for a concrete floor with a live 3D measurement diagram.

Measurement inputs

Enter floor size and thickness. Results update live.

Live calculation
Used in the PDF report and saved report.
Switches starter units only.
◆ Recommended: 4 in thick · 3,000–4,000 PSI mix
Enter a length greater than 0.
Enter a width greater than 0.
Standard: 4 in for residential slabs. Enter a thickness greater than 0.
10% is common for normal jobs. Waste cannot be negative.
Optional. Use 0 if unknown. Cost cannot be negative.
Use waste volume for safer ordering.

Live 3D floor preview

The same SVG is used in the report.

Length 20 ft
Width 12 ft
Thickness 4 in

Result dashboard

Material estimate for the entered floor size.

Order quantity with waste
Includes 10% waste. Base floor volume is 2.96 cu yd.
3.26 cu yd
Base volume 2.96 cu yd
Cubic feet 80.00 cu ft
Cubic meters 2.27 m³
Floor area 240 sq ft
40 lb bags 294 bags
60 lb bags 196 bags
80 lb bags 147 bags
Estimated cost $456.30
This is an estimate. Check final quantity with your concrete supplier before ordering.

Formula used

All main measurements are converted to feet before calculation.

Concrete floor volume:

Volume = Length × Width × Thickness