How many rolls of wallpaper do you need?
Add your rooms or walls, get rolls of wallpaper instantly.
How do I calculate how many rolls of wallpaper I need?
Find the wall area — the perimeter of the room times the wall height — and take off about 21 square feet for each door and 15 for each window. Add 15% for matching the pattern and trimming, then divide by what one roll covers. A 12 by 12 ft room with 8 ft walls, one door and one window has 348 square feet of wall; with 15% extra that is 400 square feet, or 8 double rolls of 56 square feet.
How many square feet does a roll of wallpaper cover?
An American single roll is about 28 square feet and a double roll about 56. A European roll, the size most imported papers come in, is 0.53 by 10.05 meters — 5.33 square meters or about 57 square feet. Peel-and-stick rolls vary, often around 30 square feet, so check the label and add it as your own roll size.
How much extra wallpaper do I need for the pattern repeat?
About 10% for a random or free match, such as grasscloth and textures; 15% for a small straight-match repeat; and 20 to 25% for a large or drop-match repeat, since each strip starts further down the pattern. The repeat is printed on the label.
Why is wallpaper priced by the single roll but sold as a double roll?
It is a long-standing habit of the US trade: prices are quoted per single roll, but the paper is packed and sold in double rolls, which leave less waste per strip. When you compare prices, make sure both are for the same kind of roll.
Should I buy all the rolls at once?
Yes. Each print run, or batch, can differ slightly in color. Buy every roll you need from the same batch number, plus one spare for repairs — a matching roll can be impossible to find later.
Two ways to count: by area and by strips
The calculator uses the area method. For a 12 by 12 ft room with 8 ft walls, the walls total 384 square feet; taking off a door (21) and a window (15) leaves 348. With 15% extra that is 400 square feet, or 8 double rolls of 56 square feet. Professionals often count strips instead, because wallpaper is hung in whole strips and a roll cannot be pieced together from leftovers. The strip method shows what the area method hides: how the repeat eats paper.
Worked example: the strip method with a pattern repeat
Take European rolls, 0.53 m (about 20.9 in) wide and 10.05 m (about 33.0 ft) long. The 48 ft of wall needs 28 strips. With walls 10 ft high and plain paper, cut each strip 4 in longer than the wall for trimming: 124 in. A roll of 396 in then yields 3 strips, so you need 10 rolls. Now suppose the pattern repeats every 24 in and must be matched. Each strip has to be cut to a whole number of repeats, so 124 in becomes 144 in. A roll now yields only 2 strips, and the same room needs 14 rolls. The numbers show why a flat percentage is only an estimate; the strip method is the safer check for a large repeat, and the repeat length is printed on the roll label.
Common mistakes
- Deducting too many openings. Windows and doors are only worth deducting when they are large; small ones barely save a strip, and a strip over a window still needs the full cut above and below it.
- Forgetting the ceiling-to-baseboard allowance. Every strip is cut longer than the wall to allow for trimming at both ends.
- Comparing prices of single and double rolls as if they were the same unit, or mixing a European roll (5.33 square meters) with an American single (about 28 square feet) in one calculation.
- Ordering by the room's floor area instead of its wall area, which gives far too little paper.
Before you hang
Check every roll for the same batch number before opening the first one, because shade differences show only once strips sit side by side. Hang the first strip against a plumb line, not a corner, since walls and corners are rarely straight.
Sources: roll sizes and pattern-repeat allowances from wallpaper retailers' estimating guides (Wallpaper Boulevard, Wallpapers To Go); the strip method is the standard hand-calculation used by the trade. Related tools: paint calculator, square footage calculator, flooring calculator and baseboard calculator.