Plaster Calculator
Estimate plaster bags for walls or ceilings. Enter area, thickness, and coverage per bag from your product label.
Measurements
How this is calculated
Wall area = wall width × wall height.
Bags needed = (area ÷ coverage per bag) × (1 + wastage ÷ 100), rounded up.
A typical 25 kg bag may cover about 2–3 m² at 12 mm — always use the figure printed on your bag for the thickness you plan to apply.
Related reading
Estimates only — bag coverage depends on thickness, substrate, and product. Check the bag label and allow extra for uneven walls.