How much paint or wallpaper do you actually need? Enter your wall dimensions, doors, and windows, and this calculator works out the paintable area, coats, ceiling, primer, and — for wallpaper — full strips per roll.
Paint mode subtracts standard doors and windows, supports multiple coats and ceiling painting, adds primer estimates and a waste allowance, and can estimate material cost. Wallpaper mode uses roll width, length, wall height, trimming allowance, pattern repeat, and waste to count full strips from each roll — not just wall area.
Paint & Wallpaper Calculator
Estimate your supplies before decorating. Compare paint and wallpaper plans with a visual room preview, transparent calculations, and a practical shopping list.
Materials estimate
Prepared for your room measurements.
Where the material goes
Openings are deducted for paint. Wallpaper ordering still uses full strips.
At a glance
Results are planning estimates, not a purchase guarantee. Check coverage, packaging, surface texture, pattern matching, wall openings and product specifications. For wallpaper, half-drop or offset patterns may need extra rolls; this calculator uses a conservative straight-repeat allowance.
Explore decorating guides →How to use it:
- Choose Paint or Wallpaper mode, then Single Wall or Full Room.
- Enter your wall length and height, plus doors and windows — and set their positions (left, center, right, or evenly spaced).
- For paint, set coats, ceiling, primer, and waste allowance. For wallpaper, choose a pattern and set roll size, pattern repeat, and trimming allowance.
- Watch the preview update live as you change colors, patterns, or room settings.
- Read your material estimate and shopping list, and save the preview as a PNG image if you want to keep or share it.
Please note: wallpaper estimates are a planning aid. Always verify against the actual product label and the manufacturer’s roll specifications before buying, and allow extra for half-drop or complex offset patterns.
Your dimensions stay in your browser. Nothing is sent to us or stored.
How much paint do I need for one room?
It depends on wall area minus doors and windows, the number of coats, and whether you paint the ceiling. Enter your measurements above and the calculator works it out, including primer and a waste allowance.
Why does the wallpaper calculator count strips instead of wall area?
Wallpaper is bought by full-length strips, and pattern repeats change how many strips come from one roll. Counting strips gives a more accurate roll count than dividing wall area alone.
Should I trust the estimate or buy extra?
Use the estimate as your starting point, then check the manufacturer’s roll label and allow a little extra for pattern matching, trimming, and mistakes.
Can I download a preview of my room?
Yes. After customizing colors and patterns, use Save Preview as Image to download a PNG of your room preview.