plaster
Plaster
Calculate plaster volume and bags needed for wall finishing.
Results are approximate. Verify with manufacturer specifications or consult a professional.
Project inputs
IMPERIAL
Enter a value in ft².
Enter a value in ft.
Enter a value in yd³.
Includes breakage, spillage, onsite adjustments
Material output
Updates instantly as you type.
Primary output
130m²
130 m²
≈ 118.2 m² primary output
Plaster volume
Your units
0.05 yd³
Bags
Your units
1 ea
Results are approximate. Verify with manufacturer specifications or consult a professional.
How it works
Frequently asked questions
Country defaults
United States · USD · imperial
Waste factor: 10.0%
Context & guidance
Results are approximate. Verify with manufacturer specifications or consult a professional.
About This Calculator
Calculate the exact amount of plaster needed for walls and ceilings. Accounts for surface area, number of coats, plaster type (gypsum, cement, lime), thickness per coat, waste factors (typically 10-15% for standard applications, 15-20% for textured finishes), and country-specific coverage rates. Supports both metric and imperial units.
Step-by-Step Instructions
Measure Surface Area
For walls: measure perimeter × height, subtract doors and windows. For ceilings: measure length × width. Use the same unit system throughout. Record all measurements consistently in meters or feet.
Select Plaster Type
Choose material: gypsum plaster (typical coverage 1-1.5 m² per 25kg bag), cement plaster (0.8-1.2 m² per 25kg bag), or lime plaster (varies). Coverage depends on thickness and application method.
Determine Number of Coats
Standard application: 2 coats (scratch coat + finish coat). Some applications need 3 coats (base + scratch + finish). Each coat typically 2-5mm thick. Thicker coats = more material needed.
Account for Waste Factor
Standard smooth finishes need 10-15% waste for application losses and touch-ups. Textured finishes (stucco, decorative) need 15-20% waste due to thicker application and pattern work.
Calculate Material Needed
The calculator shows: total area, plaster weight/volume needed (including waste), and number of bags required. Always round up to full bags. Order 5-10% extra for future repairs.
Order Materials
Order all plaster from the same batch for color consistency. Buy 5-10% extra for future repairs. Store in a dry location. Calculate primer separately if required for the substrate.
Common Mistakes
Not accounting for number of coats
Each coat requires material. A 2-coat application needs roughly 2× the material of a single coat. Always specify number of coats accurately. Standard is 2 coats (scratch + finish), some applications need 3.
Forgetting to subtract openings
Doors and windows reduce plaster needs. Standard door: ~2.0 m², single window: 1.5-2.5 m². Always measure and subtract all openings accurately.
Underestimating waste for textured finishes
Textured finishes (stucco, decorative patterns) require 15-20% waste vs 10-15% for smooth finishes. Thicker application and pattern work increase material needs significantly.
Not ordering extra for future repairs
Always order 5-10% extra from the same batch. Plaster colors vary between batches, and you'll need matching material for future repairs or damage.
Pro Tips
Buy all plaster from the same batch. Color variations between batches are noticeable, especially with tinted or colored plasters.
For textured finishes (stucco, decorative), add 20% waste instead of 15%. Textured applications use more material due to thicker coats and pattern work.
Calculate primer separately if required. Some substrates (new drywall, masonry) require primer before plastering. Primer coverage: typically 8-12 m² per liter.
Plan your application sequence. Apply scratch coat first, let it cure, then apply finish coat. Allow proper curing time between coats per manufacturer instructions.
Keep 5-10% extra plaster for future repairs. Store in a dry location in sealed containers to prevent moisture damage.
For exterior applications, use weather-resistant plaster (cement-based). Interior applications typically use gypsum plaster. Coverage may differ between types.
Frequently Asked Questions
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