Wallpaper Calculator

How to use

1. 1Pick units (feet and inches or meters) and pick a measurement mode: whole room, accent wall, or list of walls.
2. 2Enter the dimensions. For a whole room, type the room length and width. For an accent wall, type one wall length. For a list, add up to six walls and type each one.
3. 3Type the ceiling height. Use feet plus optional inches in imperial mode, meters in metric mode.
4. 4Enter the pattern repeat from the back of the roll or product page, and pick the match type: none, straight, or half-drop. Leave repeat at 0 for solid colors and textures.
5. 5Set the door and window count. Use the standard opening sizes or switch to custom and type the average door and window dimensions. Toggle Subtract openings on or off to match your installer's habit.
6. 6Pick the roll size that matches your product, or choose Custom roll size and type the exact width and length printed on the listing.
7. 7Add a waste allowance: 10% is the conventional default, 15% for busy patterns and tricky rooms.
8. 8Optionally enter the price per roll and a currency to get a total cost.
9. 9Read the rolls-needed number, the strips needed, drops per roll, cut length per strip, wall area, and the leftover area. Use Copy plan to grab a summary for your shopping list.

About this tool

Wallpaper Calculator answers the question every wallpaper shopper asks at the till: how many rolls do I actually need? The math is rooted in the standard installer formula. Coverage length (room perimeter for a whole room, the single wall length for an accent wall, or the sum of walls in a list) is divided by the roll width to get the number of vertical strips, then the wall height (plus a small trim allowance) is divided into the roll length to get the number of full drops you can cut from one roll. Rolls needed equals strips needed divided by drops per roll, rounded up. The hard part is pattern repeat. If a wallpaper has a vertical repeat (the same image element appears every X centimetres), every drop has to be cut to a whole multiple of that repeat so adjacent strips line up. The tool rounds the cut length up to the next whole repeat for straight-match papers. For half-drop match, where every other strip starts at half the repeat (the most common designer style), it adds half a repeat per strip on average, which matches the rule of thumb in installer manuals and the calculators most wallpaper retailers publish. Roll presets cover the standard Euro double roll (0.53 m by 10.05 m, the global default for residential lines), the older Euro single roll (0.56 m by 5 m), American double and single rolls (27 in wide), the wider US grass cloth and commercial roll (36 in), and the typical peel-and-stick removable size (24 in by 15 ft). Doors and windows can be subtracted by area, with a default opening size of 0.9 by 2.1 m for doors and 1.2 by 1.3 m for windows; many professional installers do not subtract opening area because cuts get used at headers, sills, and the top of doorways, so the subtract-openings toggle is here. A waste allowance defaults to 10% (the conventional figure on installer worksheets) and can be raised to 15% for busy patterns, tricky corners, or first-time DIY. Cost is optional: enter the price per roll and a currency to get a total. All computation runs locally; nothing is uploaded. This is a planning estimate, not a guarantee; for irregular walls, bay windows, ceilings, or any project with murals or panels, buy one extra roll and keep a record of the batch number.

Free to use. Works in your browser. No signup, no login.