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Cement-Sand-Aggregate Mix Calculator

Convert finished concrete volume and a volume ratio into dry material volumes and approximate cement bags.

Estimate cement, sand and aggregate for a nominal mix

Convert finished concrete volume and a volume ratio into dry material volumes and approximate cement bags.

Dry material volume—
Cement volume—
Approx. cement bags—
Sand volume—
Aggregate volume—

How the cement-sand-aggregate mix calculator works

The calculator applies an editable dry-volume factor to the finished concrete volume, then splits that dry volume according to the entered cement:sand:aggregate ratio. Cement volume is converted to mass using an editable bulk density and then into bags.

Where this construction calculation helps

Use this for preliminary material planning for nominal mixes, small non-critical works or cross-checking hand calculations.

Measurements and assumptions

The familiar dry-volume factor and bulk density are approximations, not universal constants. Moisture, voids, aggregate grading and mix design affect yield. Reinforced or structural concrete should be produced from the specified mix design, not a generic nominal ratio.

Worked example

For 1 m³ finished concrete with a 1:2:4 nominal ratio and 1.54 dry factor, dry material volume is 1.54 m³, divided across seven ratio parts.

Use nominal mix quantities as an estimate, not a structural design

This cement, sand and aggregate mix calculator converts a selected nominal proportion into approximate ingredient quantities. Actual concrete yield depends on moisture, bulking, aggregate grading, compaction and the relationship between dry ingredient volume and finished concrete volume. Structural concrete should follow the specified mix design, strength class and local code rather than a generic site ratio. For purchasing, add an appropriate site allowance and compare the calculated quantities with batching practice and supplier units.

Frequently asked questions

Why is dry material volume higher than finished concrete volume?
Loose dry ingredients contain voids and settle when mixed, so planning methods often use a dry-volume allowance.
Is 1.54 always the correct factor?
No. It is a common estimating assumption, so the tool makes it editable.
Can I use this for structural concrete?
Use the project engineer's specified mix design for structural work. A nominal ratio calculator is not a substitute for engineered batching.
Why is cement density editable?
Bulk density varies with material condition and measurement method, so an editable value is more transparent than a hidden constant.