1. What is This Calculator?

This calculator determines the amount of cement and sand needed for concrete mixtures based on volume and specified ratios, using standard densities for materials (90 lb/ft³ for cement, 100 lb/ft³ for sand).

2. How Does the Calculator Work?

The calculator uses these formulas:

Where:

• Volume — Total volume of concrete needed (cubic feet)
• Sand ratio — Proportion of sand in the mix
• Aggregate ratio — Proportion of aggregate in the mix
• 90 — Density of cement (lb/ft³)
• 100 — Density of sand (lb/ft³)

3. Importance of Accurate Measurements

Details: Proper ratios ensure concrete has the desired strength and workability. Too much or too little of any component can compromise the final product.

4. Using the Calculator

Tips: Enter the total volume needed, then the sand and aggregate ratios you plan to use (common ratios are 2:3 or 1:2:3 for cement:sand:aggregate). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical concrete mix ratios?
A: Common ratios include 1:2:3 (cement:sand:aggregate) for general purpose concrete or 1:3:5 for foundations.

Q2: How do I convert cubic feet to cubic yards?
A: Divide cubic feet by 27 (since 1 cubic yard = 27 cubic feet).

Q3: Why are different densities used?
A: Cement and sand have different densities - cement is typically heavier per unit volume than sand.

Q4: Should I include water in the ratios?
A: No, water is typically calculated separately based on desired consistency (water-cement ratio).

Q5: How accurate are these calculations?
A: They provide good estimates but actual needs may vary based on material moisture content, compaction, and other factors.