Cement Bag Calculator

Dry construction materials (cement, sand, aggregate) have air gaps between particles before mixing. When combined with water, they compact and lose volume, so estimators use a standard 1.54 multiplier to calculate how much dry material is needed to produce the target wet, poured volume.

1:2:4 is the most common general-purpose ratio for slabs, patios, and driveways. Use 1:1.5:3 for structural elements needing higher strength, and 1:3:6 for non-structural mass fill where high strength isn't required.

This calculator focuses on cement bags specifically. Once you know your dry volume, you can apply the same ratio to estimate sand and aggregate: for a 1:2:4 mix, sand is roughly twice the cement volume and aggregate roughly four times.

Yes. This calculator already rounds up to the nearest whole bag, but ordering a small additional buffer (5-10%) is wise to cover spillage, mixing losses, or minor thickness variations across the slab.

Yes. Use the "Copy Summary" button to copy your results to your clipboard, or "Share Tool" to send the calculator link to your contractor or supplier.