Wallpaper Calculator
Estimate rolls of wallpaper for a room.
Enter your total wall area, subtract doors and windows, and set your roll's usable coverage to get the number of wallpaper rolls. A generous waste allowance is included because pattern matching wastes more than you'd expect.
How it works
Subtract openings from the wall area, add waste for pattern repeat and trimming, then divide by the usable coverage per roll. Patterned papers waste more than plain, so 15% or more is sensible. Buy from the same batch to avoid color shifts.
Frequently asked questions
How many rolls of wallpaper do I need?
Subtract openings from the wall area, add about 15% for pattern matching, then divide by the usable coverage per roll. A 400 sq ft room with 40 sq ft of openings needs about 14 rolls at 30 sq ft usable each.
Why is wallpaper coverage less than the roll size?
Pattern repeats and trimming waste mean a roll's usable area is well below its printed size — often only about half on large repeats.
Should I buy all rolls from the same batch?
Yes — colors can shift slightly between print runs, so order the same batch number and buy a spare roll.
Is this calculator free and private?
Yes. Every CubicCabin calculator runs entirely in your browser, so the numbers you enter are never uploaded or stored. There's no sign-up, no limits, and it keeps working even if you lose connection after the page loads.