Plaster & Board Calculator

Calculate cement bags for sand-cement render, or the number of plasterboards for dry-lining.

Enter your measurements

Surface Area m²

Render Thickness mm

Results

Render Volume0.300 m³

Cement (50kg bags)4

Plasterboards 1200×2400mm9

1:3 cement:sand plaster mix; plasterboard = 1.2×2.4m = 2.88 m²

How it works

Render volume is surface area multiplied by thickness. For a 1:3 cement-to-sand mix — standard in Nigeria — approximately 12 bags of cement are needed per cubic metre of render. Plasterboard count is total area divided by 2.88 m² (the size of a standard 1200×2400mm board), rounded up.

Formula

Volume (m³) = Area × (Thickness / 1000)
Cement bags = Volume × 12
Boards = ceil(Area / 2.88)

Tips for accurate results

1The standard plaster thickness for internal walls in Nigeria is 12mm applied in two coats.

2Allow 10% extra bags to account for mixing losses and uneven substrate.

3For bathroom walls that will be tiled, use cement-based waterproof render — not gypsum plaster.

4Apply render in two coats: a 10mm scratch coat first, then a 3–5mm finish coat for best results.

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