Calculate paint
How much paint do you need?
Enter the area and number of coats to see how much paint and how many buckets you need — for interior, exterior, ceiling or roof.
Details: doors, windows, primer
You need Example
0 L
Bucket size and number—
How this was worked out
- Area to paint
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- Coats
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- Coverage (per coat)
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- Primer (approx.)
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- Wall area
2 × (width + length) × height - Net area
wall area − doors × 2 m² − windows × 1.5 m² - Paint
net area × coats ÷ coverage (middle of the range) × 1.10 waste allowance - With primer
primer = net area ÷ primer coverage × 1.10 (one coat); the top coat does not change - Buckets
the product's own packs, least left over and fewest buckets
An estimate: middle of the coverage range plus 10% waste. The surface and the colour change consumption.
Consumption by surface
Coverage and coats by surface.
Single-coat catalogue coverage of the suggested product. On rough and coarse surfaces use the low end of the range.
| Surface | Suggested product | Coverage — one coat | Recommended coats |
|---|---|---|---|
| Interior (smooth) | Pro Mat Interior Wall Paint | 8–12 m²/kg | 2 |
| Interior (rough) | Pro Mat Interior Wall Paint | 8–12 m²/kg (low end: 8 m²/kg) | 2–3 |
| Exterior (smooth render) | Silicone Elite Matt Exterior Paint | 8–10 m²/L | 2 |
| Exterior (rough render) | Silicone Elite Matt Exterior Paint | 8–10 m²/L (low end: 8 m²/L) | 2–3 |
| Ceiling | Pro Ceiling Paint | 7–10 m²/kg | 2 |
| Roof tiles and roofs | Silicone Tile Paint | 4–6 m²/L | 2 |
| Product | Coverage — single coat (catalogue) | Packaging |
|---|---|---|
| Pro Mat Interior Wall Paint | 8–12 m²/kg | 20 kg · 10 kg · 3.5 kg |
| Silicone Elite Semi-Matt Interior Wall Paint | 12–18 m²/L | 15 L · 7.5 L · 2.5 L |
| Silicone Elite Soft Mat Interior Wall Paint | 12–18 m²/L | 15 L · 7.5 L · 2.5 L |
| Silicone Elite Matt Exterior Paint | 8–10 m²/L | 15 L · 2.5 L |
| Silicone Pro Mat Exterior Paint | 8–10 m²/L | 15 L · 2.5 L |
| Silicone Lunateks Textured Exterior Coating | 1–1.5 m²/kg | 25 kg |
| Pro Ceiling Paint | 7–10 m²/kg | 17.5 kg · 10 kg · 3.5 kg |
| Silicone Tile Paint | 4–6 m²/L | 15 L |
| Concrete Primer | 4–5 m²/kg | 12 kg |
| 1/7 Concentrate Clear Primer | 45–65 m²/L | 15 L · 2.5 L |
| Silicone Exterior Primer | 10–12 m²/kg | 20 kg · 3.5 kg |
| Opaque Acrylic Primer | 10–12 m²/kg | 20 kg · 3.5 kg |
Measure
Measure each wall in metres; deduct ~2 m² per door and ~1.5 m² per window.
Add a margin
The calculator adds 10% for waste; this is a Luna Tones assumption, not a TDS value.
Use a primer
The product's technical data sheet names its primer; the calculator works out one coat of it separately.
One batch
Avoid buying the same colour from different production batches.
Mind the temperature
Bring paint to 15–20 °C room temperature before use.
Dark colours
Two coats suit light tones; dark tones may need three.
A primer creates a bonding layer between the paint and the surface. It is essential on new plaster, bare concrete and repaired areas.
If you tick "I will use a primer", one coat of the primer for that surface is calculated as well: Opaque Acrylic Primer indoors and on ceilings, Silicone Exterior Primer outdoors. The top coat does not change.
Related products
Frequently asked questions
About paint calculation.
How much paint do I need for 100 m² of wall?
With Pro Mat Interior Wall Paint (8–12 m²/kg), 100 m² of net wall in 2 coats needs 16.7–25 kg; the calculator suggests 22 kg (middle of the range plus 10% waste). Rough surfaces and dark colours need more.
Why is exterior paint different from interior paint?
Exterior paints are formulated to withstand UV light, moisture and changes in temperature. In the catalogue our exterior paints cover 8–10 m²/L; our interior paints sold by the litre cover 12–18 m²/L.
Does the calculation include primer?
The calculator works out the top coat. If you tick "I will use a primer", one coat of the primer for that surface is shown as well; the top coat does not change.
How many coats do I need?
Two coats are enough for most surfaces. Going from a dark to a light colour, new plaster or very dirty surfaces may need three. Wait the drying time given in the product's technical data between coats.
How do I calculate roof-tile paint?
Measure the roof area in m² along its pitched surface. Silicone Tile Paint covers 4–6 m²/L; use that figure.
Which units does the calculator use?
Measurements are entered in metres (m) and square metres (m²). For interior and exterior walls the area is worked out from the room dimensions; for ceilings and roofs you enter the area in m². The result is in litres or kg, as the product is sold.
Not sure about the result?
Our technical team will help you choose the right product and quantity.
