Concrete Cement Sand Gravel Calculator

Concrete Mix Formulas:

\[ \text{Cement (kg)} = \left[\text{Volume (m³)} \times 1.54 \times \left(\frac{1}{1 + \text{sand ratio} + \text{gravel ratio}\right)\right] \times 1440 \] \[ \text{Sand (m³)} = \text{Volume (m³)} \times 1.54 \times \left(\frac{\text{sand ratio}}{1 + \text{sand ratio} + \text{gravel ratio}}\right) \] \[ \text{Gravel (m³)} = \text{Volume (m³)} \times 1.54 \times \left(\frac{\text{gravel ratio}}{1 + \text{sand ratio} + \text{gravel ratio}}\right) \]

Volume:

m³

Sand Ratio:

(unitless)

Gravel Ratio:

(unitless)

Cement Density:

kg/m³

Cement Required:

Sand Required:

Gravel Required:

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1. What is Concrete Mix Calculation?

The concrete mix calculation determines the exact quantities of cement, sand, and gravel needed for a specific volume of concrete, based on the desired mix ratios.

2. How Does the Calculator Work?

The calculator uses these formulas:

Where:

1.54 — Conversion factor for dry volume to wet volume
1440 — Default cement density (can be adjusted)
Sand ratio — Proportion of sand in the mix
Gravel ratio — Proportion of gravel in the mix

3. Importance of Accurate Material Calculation

Details: Precise calculation ensures the concrete has the right strength and workability while minimizing waste and cost.

4. Using the Calculator

Tips: Enter the total volume of concrete needed, your desired sand and gravel ratios (common ratios are 1:2:4 or 1:3:6 for cement:sand:gravel), and cement density (default is 1440 kg/m³).

5. Frequently Asked Questions (FAQ)

Q1: What are typical mix ratios?
A: Common ratios are 1:2:4 (general purpose) or 1:3:6 (foundations). The first number is always cement.

Q2: Why the 1.54 multiplier?
A: This accounts for the increase in volume when mixing dry materials with water (bulking).

Q3: How accurate are these calculations?
A: They provide good estimates but actual needs may vary slightly based on material quality and compaction.

Q4: Should I account for waste?
A: It's common to add 5-10% extra to account for spillage and uneven surfaces.

Q5: Can I use this for different concrete grades?
A: Yes, by adjusting the mix ratios. Higher cement content creates stronger concrete.