Wallpaper Calculator

Use it when your task matches one of these common needs: Estimate rolls for a bedroom, office, or powder room. Subtract common doors and windows from wall area. It works best when you already know the measurements, amounts, units, or options the page asks for.

In plain language: The calculator finds wall area from room perimeter and height, subtracts estimated doors and windows, adds waste, divides by roll coverage, rounds up, and multiplies by roll price when entered. The examples on the page are there so you can compare your inputs with a worked example before copying the answer.

Room length and width: the two pairs of walls used to estimate total wall area from room perimeter. Wall height: the average height from the floor or baseboard to the ceiling, trim, or stopping point. Doors and windows: standard openings subtracted from wall area before waste is added. Roll coverage: usable square feet one roll covers; use the product label before trying to calculate it from roll width and roll length. Waste percent: extra wallpaper for trimming, matching patterns, damaged strips, corners, and mistakes. Price per roll: optional roll price used only for a rough material cost before tax, shipping, paste, tools, or labor.

Read the headline estimate first, then check the material, waste, coverage, and unit lines. For project tools, the supporting lines are often the difference between a rough idea and a list you can actually shop from.

Wallpaper needs can change with pattern repeat, usable roll yield, accent walls, odd wall shapes, trimming, damaged strips, product returns, and dye lots. Also check the unit, scale, mode, and result limit because small input changes can change the answer.

Waste percent is extra wallpaper added before the roll count is rounded up. It covers the pieces you cut off at the ceiling and baseboard, strips that need to shift so the pattern lines up, damaged pieces, and small measuring mistakes. If the wall math says you need 300 square feet and you enter 10% waste, the calculator plans for 330 square feet before dividing by roll coverage.

Use 10% as a simple starting point for plain, random-match, or easy peel-and-stick wallpaper. Use about 15% when there is a normal pattern repeat or several corners and openings. Use 20% or more for large pattern repeats, drop matches, older uneven walls, or if you want spare paper for repairs. The product label and installer advice should win when they give a specific number.

Roll coverage is the usable square feet from one roll or bolt. Do not guess this from the roll size if the product page already gives coverage, because pattern repeat can lower the amount that actually lands on the wall. Some products are priced as single rolls but shipped as double rolls, so check whether the coverage number belongs to the roll you are buying.

A repeating pattern has to line up from strip to strip. That means a strip may need to be cut longer than the wall height so the design starts in the right place. The extra cut-off part is not a mistake; it is the cost of making the pattern match instead of looking shifted.

Multiply roll width by roll length only as a fallback. The better input is the usable coverage printed on the wallpaper label or product page, because sellers may list single rolls, double rolls, bolts, or coverage after pattern repeat. If the label says one roll covers 56 square feet, use 56 even if the raw width times length looks different.

The room fields use feet, so convert inches to feet before entering them. Divide inches by 12. For example, 108 inches is 9 feet. If you only have roll width and roll length in inches, convert both to feet before multiplying them, or use the usable roll coverage from the product label when it is listed.

A 12 x 12 room with 8-foot walls has about 384 square feet of wall area before openings. One standard door and two standard windows bring that to about 334 square feet. With 10% waste, the calculator plans for about 367 square feet. If each roll covers 56 square feet, that rounds up to 7 rolls.

For one accent wall, do not enter the whole room unless all walls are being covered. Estimate that wall area separately, subtract major openings if needed, then use the roll coverage and waste percent from the wallpaper you plan to buy. If the accent wall has a large pattern, keep the waste percent higher than a plain texture.

For a rough estimate, subtracting standard doors and windows keeps the roll count from getting too high. For peel-and-stick or patterned wallpaper, some stores advise not subtracting openings because you still cut around them and may need full-height strips. If you are close to the next roll, it is usually safer to round up.

Wallpaper can have tiny color differences between print runs. The lot, run, or batch number helps you buy rolls printed together. If you buy more later from a different lot, the pattern may be correct but the color can still look slightly off on the wall.

Yes. Add a price per roll if you want a rough material cost. The calculator multiplies that price by the whole rolls needed, but it does not include tax, shipping, paste, primer, tools, returns, or labor. Use it as a quick shopping check, not a contractor quote.

No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.