Plastering Calculator
Enter the surface size, plaster thickness and mortar mix. Deduct openings and choose one or two sides.
Your result will appear here after you press Calculate.
How this calculator works
Plaster area = (length × height − openings) × number of sides
Wet mortar = plaster area × thickness
Dry mortar = wet mortar × dry factor × (1 + wastage ÷ 100)
Cement = dry mortar ÷ (1 + sand part); Sand = dry mortar × sand part ÷ (1 + sand part)
Assumptions and limits
- Typical thickness is about 12 mm for walls and 6 mm for ceilings; use the value specified for your work.
- Dry factor 1.27 and 50 kg cement bags at 1440 kg/m³ are editable/stated assumptions.
- Surface unevenness and absorption can raise actual consumption.
This tool gives an approximate estimate from the values you enter. It is not a substitute for professional engineering design, site inspection, official quotations or applicable building regulations. See the calculator disclaimer.