Paint, Flooring & Tile Coverage Calculator

How the calculator works

• Paint: Walls area = perimeter × height minus openings. Ceiling is length × width. Multiply by coats, then divide by coverage (m² per litre). Tins round up.
• Flooring: Area = length × width. Add waste %, divide by pack coverage, round up packs.
• Tiles: Effective tile size = tile + spacing on both edges. Tile count = area ÷ effective tile area, add waste %, round up tiles/boxes.

Best Practices for Paint, Flooring & Tiling

Paint: prep smart for smoother coats

• Surface prep first: Fill, sand, and dust off. Grease or gloss? Clean, then lightly sand to key the surface. Fresh plaster should be dry and mist-coated (diluted first coat) before full coats.
• Primer matters: Use stain-blocking primer over knots, water marks, or marker. On bare wood, use appropriate wood primer; on shiny trim, an adhesion primer prevents peeling.
• Right tools: Walls: medium-pile roller; ceilings: longer pile; doors/trim: quality synthetic brush. Extendable poles improve speed and posture.
• Cut in + roll: Cut the edges, then roll while the cut line is still wet to avoid “picture framing.” Work one wall at a time.
• Coats & coverage: Most emulsions cover ~10–12 m²/L (check the tin). Dark colours or drastic colour changes often need an extra coat or tinted primer.
• Dry times & ventilation: Respect recoat times; high humidity slows curing. Keep rooms ventilated. Choose low-VOC paints for better indoor air quality.
• Openings & ceilings: Subtract doors/windows from wall area; add the ceiling if you’re refreshing the room fully. Our calculator handles both.
• Safety: Masking, dust extraction, eye protection, and stable ladders beat speed every time.

Flooring: stable base, tidy finish

• Check flatness: Subfloors should be clean, dry, and level to the manufacturer’s tolerance. Use a straightedge; self-levelling compound can fix dips.
• Moisture testing: Concrete must be dry enough for the floor type or a suitable DPM (damp-proof membrane) is required. Timber subfloors need to be sound and fixed.
• Acclimatise boards: Many laminates/engineered boards need 24–48 hours in the room before fitting. Keep packs flat and sealed per instructions.
• Underlay & expansion: Choose underlay for acoustic, thermal, and moisture needs. Leave expansion gaps (often 10–12 mm) around edges and fixed objects; use trims to cover.
• Layout planning: Dry-lay the first few rows and aim to avoid slivers (<60 mm). Stagger end joints (e.g., by ≥300 mm) for strength and aesthetics.
• Waste allowance: Straight planks typically need 5–10% extra; complex layouts or herringbone may need more. Our tool defaults to 10% but you can adjust.

Tiling: crisp lines, long-lasting installs

• Substrate & waterproofing: Use tile-backer boards where possible; in wet zones (showers), tank the area. Flexible, cement-based adhesive is common for most substrates.
• Plan the grid: Find the centre lines and dry-lay to avoid tiny cuts at edges. Use spacers matched to tile size and style (e.g., 2–3 mm for rectified porcelain; larger for rustic tiles).
• Large-format tips: Back-butter tiles >300 mm for better coverage. Consider a levelling clip system to minimise lippage.
• Movement joints: Honor building movement—leave perimeter gaps and use silicone (not grout) at changes of plane. Use expansion profiles on large runs per standards.
• Cuts & edges: Plan trims (metal or PVC) at external corners and exposed edges. Allow extra waste (often 10–15%) for patterned layouts or heavy cutting.
• Grout & sealing: Choose grout type for joint width and traffic. Seal natural stone and some grout types as specified; follow cure times before wet use.
• Slopes & drains: Wet rooms need consistent falls toward the drain—confirm before tiling; don’t try to “tile in” large height corrections.

Eco & aftercare

• Low-VOC choices: Select low-odour, low-VOC paints and adhesives where possible.
• Dispose responsibly: Don’t pour leftover paint or adhesive down drains. Many councils offer paint recycling or special waste facilities.
• Maintenance: Use felt pads under furniture on new floors, avoid steam mops if the manufacturer forbids them, and clean grout with pH-appropriate products.

Use the calculator above to size materials, then round up sensibly for colour matching and batch consistency. When in doubt, follow the manufacturer’s datasheet for the exact product you’re using.