How much wall does one roll of wallpaper cover?

A standard roll is about 20.5 inches (0.52 m) wide and 33 feet (10.05 m) long, roughly 56 square feet (5.2 m²). But usable coverage drops once you account for trimming and pattern matching, which is why the roll count is based on whole strips, not raw area.

Why does the pattern repeat change how many rolls I need?

With a patterned wallpaper, every strip must start at the same point in the design, so each drop is cut up to the next full repeat. A large repeat wastes the offcut at the top of each strip, so you get fewer usable strips per roll and need more rolls.

Wallpaper Calculator — How Many Rolls Do I Need? (Free)

Q: Should I subtract doors and windows?

Not for normal windows and doors — the short strips above and below them are cut from offcuts, so you still hang a full-height strip around the whole room. Only subtract a drop for a very wide opening, like a patio door or a run of built-ins, that removes a full strip width of wall.

How to calculate how many rolls of wallpaper you need

Wallpaper is not just an area problem. Because every strip has to line up with its neighbor, you cut each length to a whole number of pattern repeats and throw away the offcut — so the honest way to count rolls is by strips, the way professional hangers do:

Measure the wall width. Walk the perimeter of the room and add up the wall lengths you are papering. For a rectangular room that is 2 × (length + width).
Set the drop length. Take the wall height and add a trim allowance (about 4 in / 10 cm) for the top and bottom. If the paper has a pattern repeat, round that drop up to the next whole repeat so strips match.
Find strips per roll. Divide the roll length by one drop length and round down — a roll gives you a whole number of usable strips.
Count strips, then rolls. Divide the wall width by the roll width to get the strips you need, then divide by strips per roll and round up to whole rolls.

Why the pattern repeat matters

Say your wall is 8 ft high and you add a 4-inch trim allowance, so each drop needs about 8.33 ft of paper. On a plain paper you cut exactly that much per strip. Add a 21-inch pattern repeat and each drop is forced up to the next whole repeat — 8.75 ft — so you throw away roughly 5 inches at the top of every strip just to make the design line up. On a tall wall or a paper with a big repeat, that lost offcut is enough to remove a whole strip from each roll, so a job that looked like "area ÷ roll size" quietly needs an extra roll or two. That waste is invisible to a simple area calculator, which is exactly why patterned jobs so often come up short.

How much does a roll of wallpaper cover?

A common modern roll is about 20.5 in (0.52 m) wide and 33 ft (10.05 m) long — roughly 56 sq ft (5.2 m²) of paper. In practice you never get all of that onto the wall: trimming and pattern matching eat into it, and real-world usable coverage is often closer to 25–30 sq ft per roll for a patterned paper. American papers are frequently sold as double rolls, so the numbers above reflect that; always confirm the width and length on your roll's label and type them in.

What this calculator assumes

Straight-match or plain paper hung in full-height drops around the room.
Default roll = 20.5 in wide × 33 ft long (0.52 m × 10.05 m); edit both to match your product.
Default trim allowance = 4 in (10 cm) total for top and bottom; increase it for uneven ceilings or floors.
Normal doors and windows are not subtracted — offcuts cover the short pieces above and below them. Use "full drops to skip" only for openings a full strip wide.
Results are rounded up to whole rolls, since paper is sold by the roll.

Frequently asked questions

What is a "pattern repeat" and where do I find it?

It is the vertical distance before the design starts over — printed on the roll label or product page, often as "repeat" or "vertical repeat." A plain or random-match paper has no repeat, so enter 0. Larger repeats waste more paper per strip.

Straight match vs. drop match — does it change the count?

Both force each strip to a whole repeat, so this calculator covers them. A half-drop (offset) match wastes a little more because alternate strips shift by half a repeat; if your paper is a drop match, add roughly 10–15% or one extra roll to be safe.

Should I subtract doors and windows?

Usually no. You still hang a full-height strip across the whole wall, and the short pieces above a door or below a window come from the offcuts. Only use "full drops to skip" when a single opening — a patio door, a fireplace, a wide wardrobe — removes a full roll-width of wall.

Why buy from the same batch?

Wallpaper is printed in batches (dye lots) that can differ slightly in shade. Buy all your rolls — plus a spare — from one batch number so the walls match, and keep the spare for future repairs.