🎨 Paint Calculator

Net Paintable Area = Total Wall Area - Door Area (2.0 × 0.9 = 1.8 m² each) - Window Area (1.2 × 1.0 = 1.2 m² each) Paint Needed (L) = Net Area × No. of Coats / Coverage per Litre Tins to Buy = Ceil(Paint Needed / Tin Size) Example: 4m × 3.5m room, 2.8m ceiling, 1 door, 2 windows Wall area = (4+3.5+4+3.5) × 2.8 = 42 m² Ceiling = 4 × 3.5 = 14 m² Deduct = 1×1.8 + 2×1.2 = 4.2 m² Net area = (42 + 14) − 4.2 = 51.8 m² 2 coats, 14 m²/L: Paint = 51.8 × 2 / 14 = 7.4 L Tins = 2 × 4L tins

Economy emulsion: 12–13 m²/L Standard emulsion: 14–16 m²/L Premium emulsion: 16–18 m²/L Exterior emulsion: 10–12 m²/L Texture paint: 8–10 m²/L Masonry paint: 7–10 m²/L Primer / undercoat: 10–12 m²/L Gloss / enamel (metal): 14–16 m²/L Wood paint: 12–14 m²/L Note: Coverage reduces on rough/porous surfaces. Always buy 10% extra for wastage and touch-ups.

New plaster / bare walls: Always use primer Changing from dark to light: Use white primer Previously painted (good): Usually skip primer Stained/water-marked walls: Stain-block primer Old chalky/flaking paint: Sand + seal first Primer typically reduces final coats needed from 3 to 2, saving overall paint cost.