What units should I use?

Length/height in meters (m), area in m², layer thickness in mm. For bags mode, use consumption in kg/m² per 10 mm as shown on the bag.

Why is it only an estimate?

Real consumption depends on substrate flatness, losses, tools and application technique. Add 5–15% extra as a safety margin.

Plastering Calculator

Q: Which mode should I choose: bags or cement+sand?

If you buy a ready dry plaster mix in bags, choose “Bags”. If you mix plaster yourself (cement + sand), choose “Cement + sand”.

Estimate materials for plastering: dry mix (bags) or cement + sand. Includes chart, materials table, copy and CSV (Excel).

Auto-calc

Enter inputs

Construction

Mode

Wall: enter length and height. Area: enter only m².

Plaster type

Choose what you want to estimate: bags or cement-sand mix.

Length (m)

Height (m)

Area (m²)

Openings area (m²) (opt.)

Total windows/doors area. Subtracted from plaster area.

Layer thickness (mm)

Average thickness. Add extra for uneven walls.

Consumption (kg/m² per 10 mm)

Use the value from the bag. Typical 8–10 kg/m² per 10 mm.

Bag weight (kg)

Water (L per 1 kg) (opt.)

Leave empty if unknown — water won’t be calculated.

Formula: kg = area × consumption × (thickness/10) × (1 + waste%).

Ratio (by volume)

Cement (C)

Sand (S)

Water/cement (W/C)

• 1:3 means 1 part cement + 3 parts sand (by volume).
• W/C = 0.5 means ~0.5 L water per 1 kg cement.
• Typical: 1:3 or 1:4 • W/C ~ 0.45–0.6

Cement density (kg/m³)

Sand density (kg/m³)

Cement bag weight (kg)

Waste / extra, %

Typical 5–15% depending on losses and surface.

Waste / extra, %

Typical 5–15% depending on losses and surface.

Result

CalcCore

Enter inputs to calculate.

Chart

Visualization of key values (depends on selected mode).

Materials table (open)

Item	Qty	Unit	Note

Material cost (optional)

Mix: price per bag

In cement+sand mode, this means “cement price per bag”.

Sand: price per 1 m³

Water: price per 1 L (opt.)

Delivery (fixed)

Waste/extra, % (for cost)

Separate from material quantity waste.

Enter prices to see the total cost.

Flooring Calculator Calculate bricks quantity

How the plastering calculator works

This calculator helps you estimate how much material you need for plastering walls: either ready dry mix in bags or a DIY cement + sand mortar. It’s designed for quick planning and budgeting.

Who it’s for

Contractors and foremen — fast quantity and cost estimates.
Homeowners — to know how many bags to buy.
Early budgeting — before doing perfect measurements.
Before purchase — to add a reasonable waste margin.

Two calculation modes

1) Dry mix (bags)

Enter area, layer thickness and bag consumption (kg/m² per 10 mm). The calculator estimates: total kg, number of bags, and optionally water for mixing.

2) Cement + sand (DIY)

Enter area, thickness, C:S ratio (by volume), densities and W/C. The calculator estimates: cement (kg and bags), sand (m³) and water (L).

What is included in the estimate

Openings area (windows/doors) is subtracted from total area.
Layer thickness is converted from mm to volume.
Waste margin is added to results (recommended 5–15%).
Optional cost — enter prices to get a rough budget.

This is an estimate. Real consumption depends on wall flatness, tools, application technique and losses. For uneven walls and beginners, use a higher margin (about 10–15%).

FAQ

Which mode should I choose: bags or cement+sand?

If you buy a ready dry plaster mix — choose “Dry mix (bags)”. If you mix mortar yourself — choose “Cement + sand (DIY)”.

Where do I find the consumption value (kg/m² per 10 mm)?

It’s written on the bag or in the product datasheet. Values vary between gypsum and cement mixes.

Why does the real usage differ from the calculator?

Surface unevenness, layer thickness variations, mixing losses and application technique can change real usage. Add a 5–15% margin to stay safe.

Does it include windows and doors?

Yes. Enter total openings area (m²) and it will be subtracted automatically.

What is W/C and what value should I use?

W/C is water-to-cement ratio. For example, 0.5 ≈ 0.5 L of water per 1 kg of cement. Typical range: 0.45–0.6, but adjust based on workability and conditions.