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Plaster Calculator
Calculate cement bags and sand for internal, external, ceiling or waterproof plaster work. Supports any thickness and mix ratio. Enter room dimensions or direct area for instant material quantities and cost estimate.
Plaster Calculator
Cement bags · Sand · Internal & external · Any mix ratio
Internal plaster: 12mm thickness, 1:6 cement:sand ratio. External: 20mm, 1:5. Ceiling: 10mm, 1:4. Dry volume factor 1.3 accounts for shrinkage. Door: 1.8×2.1m. Window: 1.2×1.2m.
Frequently Asked Questions
What is the standard plaster thickness in Bangladesh?
Internal wall plaster: 12mm thickness with 1:6 cement:sand ratio. External plaster: 20mm with 1:5 ratio for better weather resistance. Ceiling plaster: 10mm with 1:4 ratio (richer mix to prevent sagging). Waterproof plaster: 15mm with 1:3 or 1:4 ratio with waterproofing compound.
How many cement bags do I need for plastering 100 sqft?
For 100 sqft of 12mm internal plaster (1:6 mix): approximately 1.2–1.5 bags of 50kg cement. For 20mm external plaster (1:5 mix): approximately 2–2.5 bags per 100 sqft. Use this calculator for exact numbers based on your room dimensions.
What is the 1:6 cement to sand ratio mean for plastering?
1:6 means 1 part cement mixed with 6 parts sand by volume. This is the standard for internal plaster in Bangladesh. The dry volume factor of 1.3 is applied to account for the voids and compaction when dry materials are mixed.
Should I include doors and windows in plaster area?
No — doors and windows are not plastered. This calculator automatically deducts 1.8×2.1m per door and 1.2×1.2m per window from the total wall area when you use the room dimension input mode.