Wallpaper Calculator

How many rolls of wallpaper do I need?

Start from net wall area and divide by the coverage of one roll. Gross area is perimeter × ceiling height; subtract the total area of doors and windows to get the net figure. Rolls equal net area with waste divided by roll coverage, rounded up to whole rolls, and pattern repeat increases the waste per drop. The number that ruins estimates is roll coverage, because it varies enormously. According to the Wallcovering Installers Association, an American single roll contains 34 to 36 ft² regardless of whether it is 18 in or 36 in wide, while a metric or euro roll contains only 28 to 30 ft² per single roll [1].

Almost nothing is actually sold as a single roll. A bolt, also called a double roll, is two single rolls in one continuous strip, priced as two singles but packaged as one length specifically to reduce waste [1]. So an American bolt is roughly 68 to 72 ft² gross and a metric bolt roughly 56 to 60 ft². Usable coverage is always less than gross coverage because the top and bottom of every drop is trimmed and pattern matching consumes more. Enter the usable square footage from the label if the manufacturer publishes it, and treat this calculator as a planning estimate rather than a cutting list.

How many square feet are in a roll of wallpaper?

The industry uses two different roll systems and they are not interchangeable. American single rolls range from 18 to 36 in wide and from four to eight yards long, but each single roll contains 34 to 36 ft² whatever the dimensions [1]. Metric or euro rolls, also called euro rolls, contain 28 to 30 ft² per single roll and are usually 21 in wide by 16 ft long, or sometimes 27 in wide by 13 ft long [1]. Commercial contract wallcoverings are a third system entirely, generally 54 in wide and specified by ounces per 54 in linear yard, with Type II covering the majority of commercial interiors [2].

This is why buying by roll count rather than by area goes wrong. Fourteen metric single rolls at 28 ft² is 392 ft²; fourteen American single rolls at 36 ft² is 504 ft², nearly 30 percent more material for the same nominal quantity. Check the label for width, length, and stated square footage before you use any roll number in the calculator, and confirm whether the price you were quoted was per single roll while the product ships as bolts. When a supplier lists both gross and usable coverage, always estimate with the usable figure.

How much wallpaper do I need for a 12x14 room?

Work a full example. A 12 ft × 14 ft room has a perimeter of 2 × (12 + 14) = 52 ft. With 8 ft ceilings, gross wall area is 52 × 8 = 416 ft². Deduct 45 ft² for one standard door and one large window, leaving 371 ft² net. This is a straight-match print with a 14 in repeat, so use 15 percent waste rather than 10: 371 × 1.15 = 426.7 ft². At 56 ft² of usable coverage per metric bolt, 426.7 divided by 56 is 7.6, so the named result is 8 bolts. Buy a ninth for future repairs.

Change one input and the answer moves. The same room with 9 ft ceilings is 468 ft² gross, 423 ft² net, and 486.5 ft² with 15 percent waste, which is 9 bolts. The same room papered in American bolts at 68 ft² usable needs only 7. And the same room in a 26 in multiple-drop pattern at 30 percent waste is 482 ft², or 9 metric bolts. Always work from the specific product, and remember the calculator estimates area coverage only. It does not lay out drops, place seams at inside corners, or plan how a pattern will land at the ceiling line.

How does pattern repeat affect how much wallpaper you need?

The repeat is the vertical distance from one point on the pattern to the next identical point, and it can range from an inch or less up to the full width of the roll [2]. Every drop has to start at the same point in the pattern, so each strip is cut longer than the wall and the surplus is scrap. A random match has no specific match point, so each strip can be positioned freely, which produces the least waste of any pattern type [2]. Stripes, textures, and grasscloths typically fall into this category and are usually installed with a reverse hang.

Drop matches cost the most material. In a half-drop match each adjoining strip aligns halfway through the vertical repeat, so it takes three strips before the vertical design repeats, and odd-numbered strips match one another while even-numbered strips match each other [2]. A multiple-drop match takes four or more strips before the design repeats [2]. Practically, that means adding roughly 10 percent for random match, 15 percent for a moderate straight match, and 20 to 30 percent for large drop matches. Enter your repeat distance in inches so the calculator can carry that allowance instead of you guessing at the register.

Do you need to prime walls before wallpaper?

Prepare the substrate to the right level of finish first. GA-214 places wallcoverings at Level 4 for smooth wall designs, which is two separate coats of joint compound over flat joints, one over interior angles, and three over fastener heads, and it reserves Level 3 for heavy-duty commercial wallcoverings only [3]. It also warns that the weight, texture, and sheen of the wallcovering must be evaluated, that joints and fasteners must be adequately concealed for lightweight or low-pattern products, and that unbacked vinyl wallcoverings are not recommended over a Level 4 finish [3]. Priming is recommended before decoration at these levels [3].

Adhesive choice follows the product, not habit. Cellulose pastes hold about 97 percent water and are intended for lightweight materials such as murals, grasscloths, paper-backed corks, and silks; clear starch-based adhesives at 60 to 70 percent water are the general-purpose option and many are strippable for use over bare sheetrock; clay adhesives at 40 to 50 percent water are made for fabric-backed commercial vinyls that need high wet tack [2]. Also record the pattern and dye lot number from each roll, because dye lots change with every print run and color can shift between batches [2]. Buy all your material at once.

How many square feet are in a roll of wallpaper?

Single and bolt definitions per the Wallcovering Installers Association. Usable coverage is after trimming and pattern matching.

How much wallpaper does each room size need?

Assumes 45 ft² of doors and windows. Add one extra bolt from the same dye lot for future repairs.

How much extra wallpaper does pattern repeat add?

Random match produces the least waste because there is no repeat distance to align. A half-drop takes three strips to repeat; a multiple drop takes four or more.

Work these out first

• wall area to coverSquare Footage Calculator
• a smooth board surface before paperingDrywall Calculator

What to do with this result

• price the rolls and adhesiveMaterial Cost Calculator

Related calculators

• painting instead of paperingPaint Calculator
• extra rolls for pattern repeatProject Waste Factor Calculator