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Wallpaper Calculator

A single 40 foot feature wall at 9 feet tall, with no pattern repeat, uses about 5 rolls of standard 33 by 20.5 inch paper. Wrap the same pattern around a full room instead and the roll count climbs fast, which is exactly why a feature wall is worth pricing on its own first.

Wall specs

Rolls to buy

Wall area0
Usable per roll0
Rolls needed0

Set width to one wall for a feature wall, or the full room perimeter for a whole-room job.

Feature wall or whole room: price both before you commit

Wallpaper's biggest cost decision usually happens before a single roll is ordered: paper one wall or paper the whole room. Enter just one wall's width for a feature wall estimate, or add up the full room perimeter (minus doors and large windows) for a whole-room job. Running both numbers through the calculator before shopping often reveals that a bold, expensive paper is affordable on a single wall and would have been a much bigger commitment across four.

Formula: strip height = ceiling height, rounded up to the next full pattern repeat. Strips per roll = roll length / strip height. Strips needed = (wall width / roll width) x (1 + waste). Rolls = strips needed / strips per roll, rounded up.

Why pattern repeat moves the roll count so much

Every strip cut from a roll has to start at the same point in the pattern as the strip next to it, or the design will not line up across the seam. A paper with no repeat uses almost the entire roll length for strips. A paper with a large repeat, say 24 inches, forces each strip to round up to the next multiple of that repeat, which throws away the leftover length at the bottom of every single strip. Small changes in this one number are why two rolls of similar-looking wallpaper can need very different order quantities.

Pattern repeatWhat it does to roll count
None (0 inch repeat)Lowest roll count; nearly the full roll length is usable
Small (under 12 inch repeat)Modest increase over no-repeat papers
Large (18 inch repeat or more)Noticeably higher roll count; budget extra rolls

A worked example, feature wall versus full room

The 40 foot feature wall in the fields above, at 9 feet tall with no repeat, needs about 5 rolls. Wrap the same paper around a full 14 by 12 room instead (perimeter roughly 52 feet, minus a door and window) and the wall width climbs to around 44 to 46 feet, pushing the order past 5 rolls even before accounting for the extra cuts around the additional corners and openings a full room has that a single flat wall does not.

Openings, corners and where the calculator is approximate

This tool works from total wall width, so a wall with a large opening will overstate the roll count somewhat since it does not subtract door and window area automatically. Subtract a large opening's width from your total before entering it. Small openings are usually fine to ignore, since the offcuts from trimming around them would often have been wasted anyway. Every internal and external corner also eats a small amount of extra paper for pattern matching, which the waste percentage field is there to absorb.

Tips before you order

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Wallpaper project questions

Is a feature wall cheaper than papering a whole room?

Almost always, since you're covering one wall's width instead of the room's full perimeter. A feature wall also lets you choose a bolder, higher-repeat pattern without the roll count climbing the way it would across four walls of the same paper.

Why did switching from a small pattern to a large repeat increase my roll count so much?

A large pattern repeat forces each strip to start at the same point in the design, which wastes the leftover length at the bottom of every strip cut from a roll. Small or no-repeat patterns use almost the whole roll length; a large repeat can waste a third of it or more per strip.

Do windows and doors reduce how much wallpaper I need?

This calculator estimates from total wall width, so large openings will overstate the roll count somewhat. For a wall with a big opening, subtract its width from the total wall width before entering it, unless the opening is small enough that the leftover strip cutoffs would have covered it anyway.

Should I buy extra rolls for a whole-room job versus a single feature wall?

Buy at least one extra roll for either job, but weigh it more heavily for a whole room, since a dye lot mismatch discovered halfway around four walls is a bigger problem than one discovered on a single wall you can still return and reorder for.

Can I mix a wallpapered feature wall with paint on the other three walls?

Yes, and it is one of the most common ways to use a bold or expensive pattern without the roll cost of covering an entire room. Run the feature wall through this calculator on its own, and use the paint calculator for the remaining walls.