How the Calculator Works:

Plaster Quantity Calculator

1. Wall Dimensions Input

• Length and Width/Height:
  You enter the length and width (or height) of the wall to be plastered.

• Unit Selection:
  You can provide these dimensions in meters, feet, centimeters, or millimeters. The calculator converts these values to meters for consistent internal calculations.

2. Openings to Exclude (Doors and Windows)

• You can input the height and width of each door or window opening separately to subtract these areas from the total wall area, ensuring you don't calculate plaster quantity for openings.

• Each opening’s dimensions can be entered with an independent unit (meters, feet, cm, or mm).

• You can add multiple doors and windows dynamically using the "+ Add Another Door" or "+ Add Another Window" buttons.

• The total opening area is the sum of the areas of all doors and windows converted to square meters.

3. Plaster Specifications

• Thickness:
  You input the plaster thickness which can be in millimeters, centimeters, or inches. It's converted internally to meters.

• Mix Ratio:
  Enter the cement to sand ratio (example: 1:4).

• Cement Bag Weight:
  Specifies the weight of one cement bag (in kg or lb), converted internally to kilograms.

4. Wet to Dry Volume Conversion Factor

• When cement and sand are mixed with water, the volume increases. The dry volume factor (typically around 1.33) accounts for this expansion, converting the calculated wet plaster volume to dry material volume for accurate material quantity estimation.

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Calculation Steps Explained:

1. Total Wall Area Calculation:

   $$\text{<span style="background-color: white;">Total Area</span>}<span\; style="background-color:\; white;">=</span>\text{<span style="background-color: white;">Length (m)</span>}<span\; style="background-color:\; white;">\times </span>\text{<span style="background-color: white;">Width/Height (m)</span>}$$

2. Opening Areas Calculation:
   Sum of the areas of all doors and windows (each converted to square meters) is calculated and subtracted from the total wall area.

3. Net Plaster Area:

   $$\text{<span style="background-color: white;">Net Area</span>}<span\; style="background-color:\; white;">=</span>\text{<span style="background-color: white;">Total Wall Area</span>}<span\; style="background-color:\; white;">-</span>\text{<span style="background-color: white;">Total Openings Area</span>}$$

4. Wet Plaster Volume:

   $$\text{<span style="background-color: white;">Wet Volume</span>}<span\; style="background-color:\; white;">=</span>{\text{<span style="background-color: white;">Net Area (m</span>}}^{\mathrm{<span\; style="background-color:\; white;">2</span>}}<span\; style="background-color:\; white;">)</span><span\; style="background-color:\; white;">\times </span>\text{<span style="background-color: white;">Thickness (m)</span>}$$

5. Dry Material Volume:

   $$\text{<span style="background-color: white;">Dry Volume</span>}<span\; style="background-color:\; white;">=</span>\text{<span style="background-color: white;">Wet Volume</span>}<span\; style="background-color:\; white;">\times </span>\text{<span style="background-color: white;">Dry Volume Factor</span>}$$

6. Material Masses and Quantities:

   • Mortar Mass:

     $$\text{<span style="background-color: white;">Mortar Mass (kg)</span>}<span\; style="background-color:\; white;">=</span>\text{<span style="background-color: white;">Dry Volume</span>}<span\; style="background-color:\; white;">\times </span>\text{<span style="background-color: white;">Mortar Density</span>}<span\; style="background-color:\; white;">(</span>\mathrm{<span\; style="background-color:\; white;">2100</span>}\text{<span style="background-color: white;">\hspace{0.17em}</span>}\mathrm{<span\; style="background-color:\; white;">k</span>}\mathrm{<span\; style="background-color:\; white;">g</span>}\mathrm{<span\; style="background-color:\; white;">/</span>}{\mathrm{<span\; style="background-color:\; white;">m</span>}}^{\mathrm{<span\; style="background-color:\; white;">3</span>}}<span\; style="background-color:\; white;">)</span>$$

   • Cement Mass:

     $$\text{<span style="background-color: white;">Cement Mass</span>}<span\; style="background-color:\; white;">=</span>\text{<span style="background-color: white;">Mortar Mass</span>}<span\; style="background-color:\; white;">\times </span>\frac{\text{<span style="background-color: white;">Cement Ratio</span>}}{\text{<span style="background-color: white;">Mix Ratio Total</span>}}$$

   • Sand Mass:

     $$\text{<span style="background-color: white;">Sand Mass</span>}<span\; style="background-color:\; white;">=</span>\text{<span style="background-color: white;">Mortar Mass</span>}<span\; style="background-color:\; white;">\times </span>\frac{\text{<span style="background-color: white;">Sand Ratio</span>}}{\text{<span style="background-color: white;">Mix Ratio Total</span>}}$$

   • Number of Cement Bags:

     $$\text{<span style="background-color: white;">Cement Bags</span>}<span\; style="background-color:\; white;">=</span>\frac{\text{<span style="background-color: white;">Cement Mass</span>}}{\text{<span style="background-color: white;">Weight per Bag (kg)</span>}}$$

   • Sand Volume:
     Using sand bulk density (~1600 kg/m³):

     $$\text{<span style="background-color: white;">Sand Volume</span>}<span\; style="background-color:\; white;">=</span>\frac{\text{<span style="background-color: white;">Sand Mass</span>}}{\mathrm{<span\; style="background-color:\; white;">1600</span>}}$$

   • Water Required:
     Estimated at roughly 0.5 liters per kg of cement:

     $$\text{<span style="background-color: white;">Water (L)</span>}<span\; style="background-color:\; white;">=</span>\mathrm{<span\; style="background-color:\; white;">0.5</span>}<span\; style="background-color:\; white;">\times </span>\text{<span style="background-color: white;">Cement Mass</span>}$$

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Why This Is Useful:

• Accurate Material Estimation:
  Prevents buying too much or too little cement and sand, saving costs and time.

• Unit Flexibility:
  Supports various units common in construction for easier data entry.

• Opening Exclusion Options:
  Eliminates plaster quantities for doors and windows to avoid overestimation.

• Dry Volume Factor:
  Adjusts for expansion during mixing — a crucial step to ensure real-world accuracy.

• Multiple Openings Management:
  Add/remove multiple doors and windows to precisely model your wall.

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How to Use:

1. Enter your wall’s length and width/height, and select the units.

2. Add each door/window’s height and width with units to exclude their areas (optional).

3. Input plaster thickness and units.

4. Specify the cement:sand mix ratio and cement bag weight with units.

5. Adjust or accept the dry volume factor (default ~1.33).

6. Click Calculate Materials.

7. View your quantities of cement (kg & bags), sand (cubic meters), water (liters), and plaster volume

🧱 Plaster Quantity Calculator

Wall Dimensions

Length:

meters feet cm mm

Width/Height:

meters feet cm mm

Openings to Exclude (Doors & Windows)

🚪 Door 1

Dimensions (H × W):

×

meters feet cm mm

🪟 Window 1

Dimensions (H × W):

×

meters feet cm mm

Plaster Specifications

Thickness:

mm cm inch

Mix Ratio (Cement : Sand):

:

Cement Bag Weight:

kg lb

Volume Conversion

Wet to Dry Volume Conversion: Mortar materials increase in volume when mixed with water. The dry volume factor corrects for this expansion.

Dry Volume Factor:

Typically between 1.25 and 1.35 for cement mortar

📊 Calculation Results

Total Wall Area: m²

Total Openings Area: m²

Net Plaster Area: m²

Wet Plaster Volume: m³

Dry Material Volume: m³

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Cement Required: kg ( bags)

Sand Required: m³

Water Required: liters