Calculate concrete volume and required cement bags, sand weight, and aggregate for slabs, footings, and columns with custom mix ratios and waste factors.
Formula and method
Concrete Volume calculates the absolute three-dimensional space of structural casting and dry ingredients (cement, sand, aggregates) based on a dry shrinkage index of 1.54 multiplier.
Raw Volume is computed: Length × Width × Thickness (depth).
If Imperial, divide total cubic feet by 27 to obtain cubic yards.
Waste margin is added to retrieve final concrete volume required.
Dry material volume totals = Wet Vol × 1.54.
Assuming M20 Grade (1:1.5:3, total parts = 5.5), Cement Bag content = Dry Vol / 5.5 × Density (1,440 kg/m³).
Frequently asked questions
How does the concrete volume calculator work?
Enter your slab, column, or wall dimensions (length, width, thickness). The calculator computes raw volume, adds waste/shrinkage margin, then calculates dry material volumes using a 1.54 multiplier. For M20 grade (1:1.5:3), it estimates cement bags, sand, and aggregate.
What concrete grades are supported?
The calculator supports standard mix ratios including M5 (1:5:10), M7.5 (1:4:8), M10 (1:3:6), M15 (1:2:4), M20 (1:1.5:3), M25 (1:1:2), and custom ratios.
Can I toggle between metric and imperial?
Yes. Switch between Metric (m, kg) and Imperial (ft, lbs) units. All inputs, material densities, and cost calculations update in real time.
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Calculations are preliminary estimates for planning and education.
Verify results against project documents and applicable codes with a licensed Professional Engineer.
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