Paint Coverage Calculator Guide: How Much Paint Do You Need?

Purchasing excessive paint leads to waste, while buying too little results in color inconsistency. Accurate calculation is critical for both economy and quality.

Basic Formula

Area (m²) = [2 × (Length × Height) + 2 × (Width × Height)] − Door and Window Areas

Example: For a room with a 4m × 5m floor area and 2.7m height, the total wall area is approximately 52 m². Subtracting a standard door (2m²) and two windows (2×1.5m² = 3m²), the net area is ~47 m².

Paint's Theoretical Coverage

The m²/L value stated on the paint packaging applies to a single coat on a smooth, non-absorbent surface. Factors affecting actual coverage: - Surface absorbency (fresh plaster absorbs more) - Application method (roller consumes 10–15% less than brush) - Color hiding power (dark colors typically require more coats) - Number of coats

Practical Calculation

For Luna Tones Pro Matt Interior, theoretical coverage is 14–16 m²/L. For two-coat application: 47 m² ÷ 15 m²/L = ~3.1 L × 2 coats = ~6.2 L

For rough or absorbent surfaces, add 15% extra → ~7.1 L. Nearest package size: 7.5 L or 10 L.

Important Note for Color Consistency

If purchasing the same paint from two separate containers, empty both into a large bucket and mix thoroughly before application (tinting). Even from the same production batch, minor color variations may occur — this mixing process prevents visible differences.

Additional Calculation for Ceilings

Ceiling area = Length × Width. For ceilings, one coat is typically insufficient — calculate for two coats.