Painting & Decorating Calculators

Painting and decorating is one of the most common home improvement activities in the UK, whether it is a single feature wall or a full house redecoration. Accurately estimating paint and material quantities prevents wastage and unnecessary expense, while ensuring you have enough to complete the job without interruption.

Emulsion paint for walls and ceilings is the staple of UK interior decorating. Leading brands include Dulux, Crown, Farrow & Ball, and Little Greene. Standard matt emulsion typically covers 12–14 m² per litre per coat, while silk and eggshell finishes cover slightly less at 10–12 m² per litre. Most walls need two coats over a mist coat (diluted first coat on new plaster), so a typical room uses more paint than many people expect. Our paint coverage calculator factors in wall area, number of coats, and your chosen paint's coverage rate to give an accurate quantity in litres.

Wallpaper is measured in standard UK rolls of 10.05m × 0.52m (approximately 5.3 m² per roll). However, the usable area per roll depends on the pattern repeat: a plain or random-match wallpaper yields more usable drops per roll than a large pattern repeat. Our wallpaper calculator accounts for room dimensions, pattern repeat, and window/door deductions to calculate the exact number of rolls needed.

For exterior work, masonry paint is used on rendered, pebbledash, and bare blockwork walls. Products like Dulux Weathershield, Sandtex, and Johnstone's Stormshield are designed to withstand UK weather conditions including rain, frost, and UV exposure. Masonry paint typically covers 5–8 m² per litre per coat, depending on the texture and porosity of the surface. Primer and undercoat are essential preparation products: bare wood needs a primer (such as Zinsser BIN or Dulux Trade Quick Dry Primer Undercoat), new plaster needs a mist coat, and previously painted surfaces in poor condition may need a stabilising solution. Our primer coverage calculator helps you quantify primer for walls, wood, and metalwork.

When decorating in the UK, preparation is everything. Proper surface preparation (filling, sanding, priming) accounts for up to 80% of the total decorating time on a professional job. Always use quality brushes and rollers appropriate to the finish: short-pile rollers for smooth finishes on emulsion, medium-pile for textured walls, and long-pile for exterior masonry. These calculators help you plan materials so you can focus on achieving a quality finish.