Plaster Calculator
Estimate cement and sand required for plastering walls or ceilings. Includes dry volume factor, wastage, and mix ratio.
How to Calculate Plaster Quantity
Plaster quantity is estimated by calculating the plastering area and multiplying it by the plaster thickness to get the wet volume. Because dry materials occupy more volume, a dry volume factor is applied. The final dry volume is then split into cement and sand using the selected mix ratio.
Plaster Mix Ratio Explained
A cement:sand ratio like 1:4 means 1 part cement and 4 parts sand. Richer mixes (lower sand part) use more cement and can be stronger, but may cost more. Always follow site requirements and local standards.
Why Thickness Matters
Small changes in thickness can significantly change material usage. Common thickness ranges are typically 10–20 mm depending on surface condition and finish.
FAQ
iHow do you calculate plaster quantity?
Compute area × thickness to get wet volume, apply dry volume factor, then split by cement:sand ratio.
What is the standard plaster thickness?
Many projects use around 12 mm for internal plaster, but it can vary by surface and finish requirements.
What is the best cement sand ratio for plastering?
Common ratios include 1:4 or 1:5. Always follow local standards and project specifications.
How many cement bags are needed per square meter?
It depends on thickness, ratio, and dry factor. Use the calculator to estimate for your exact inputs.
Why is dry volume higher than wet volume?
Dry volume accounts for voids, shrinkage, and handling loss when mixing cement and sand with water.
Disclaimer
This calculator provides an estimate only. Actual material usage can vary due to site conditions, workmanship, surface irregularities, and mixing practices. Verify with site engineers for critical work.