Plaster Cement Sand Calculation Formula

Plaster Material Calculation:

\[ \text{Cement (kg)} = \left[\text{Area (m²)} \times \text{Thickness (m)} \times 1.27 \times \left(\frac{1}{1 + \text{ratio}}\right)\right] \times 1440 \] \[ \text{Sand (kg)} = \left[\text{Area (m²)} \times \text{Thickness (m)} \times 1.27 \times \left(\frac{\text{ratio}}{1 + \text{ratio}}\right)\right] \times 1600 \]

Cement Required:

Sand Required:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Plaster Material Calculation?

The plaster material calculation determines the exact quantities of cement and sand needed for a plastering project based on the area to be covered, plaster thickness, and the mix ratio of cement to sand.

2. How Does the Calculator Work?

The calculator uses these formulas:

\[ \text{Cement (kg)} = \left[\text{Area} \times \text{Thickness} \times 1.27 \times \left(\frac{1}{1 + \text{ratio}}\right)\right] \times 1440 \] \[ \text{Sand (kg)} = \left[\text{Area} \times \text{Thickness} \times 1.27 \times \left(\frac{\text{ratio}}{1 + \text{ratio}}\right)\right] \times 1600 \]

Where:

Area — Surface area to be plastered (m²)
Thickness — Plaster thickness (meters)
Ratio — Cement to sand mix ratio (e.g., 1:4 or 1:6)
1.27 — Constant accounting for dry volume increase
1440 — Density of cement (kg/m³)
1600 — Density of sand (kg/m³)

Explanation: The calculation accounts for both the wet and dry volumes of materials, with different densities for cement and sand.

3. Importance of Accurate Calculation

Details: Proper material calculation ensures you purchase the right quantities, avoiding wastage or shortage, and helps in cost estimation and project planning.

4. Using the Calculator

Tips: Measure the area accurately in square meters. Typical plaster thickness is 12mm (0.012m) for walls and 20mm (0.02m) for ceilings. Common mix ratios are 1:4 (cement:sand) for internal walls and 1:6 for external walls.

5. Frequently Asked Questions (FAQ)

Q1: What is the 1.27 factor in the formula?
A: This accounts for the increase in dry volume compared to wet volume of mortar (about 27% more).

Q2: Why different densities for cement and sand?
A: Cement is much denser than sand (1440 kg/m³ vs 1600 kg/m³) which affects the weight calculations.

Q3: What's a typical mix ratio for plastering?
A: 1:4 (cement:sand) for internal walls, 1:6 for external walls, and 1:3 for ceiling plaster.

Q4: Should I add extra material for wastage?
A: It's recommended to add 5-10% extra to account for wastage during mixing and application.

Q5: How does thickness affect material requirements?
A: Material needs increase linearly with thickness - double the thickness means double the materials.