How Many Rolls of Wallpaper Do I Need?

If you are asking how many rolls of wallpaper do i need, start by forgetting square feet. Wallpaper is not spread across a wall like paint. It is cut into full-height strips, called drops, and hung side by side, so the honest question is how many strips your walls need and how many complete drops each roll can give you. Get those two numbers and the roll count follows. If you would rather skip the arithmetic, our wallpaper calculator does the same strip maths instantly and lets you change the room, the roll and the pattern repeat until the result matches your walls.

Quick answer: count strips, not square feet

The whole method fits in two lines. First, strips = room perimeter divided by roll width, rounded up. Second, rolls = strips divided by the number of full-height drops you can cut from one roll, rounded up again. Everything else in this guide is about doing those two divisions honestly: using the real roll size, adding a trim allowance to every drop, and rounding the drop up to the pattern repeat when your paper has one. Round up at every stage, never down, because a part strip still needs wall to cover and a part drop is waste you cannot hang.

Wallpaper roll sizes

Rolls come in a small number of standard sizes. Check the label on the paper you actually intend to buy, because the strip method depends on the width and length of that roll, not on a size you remember from a previous job.

Roll	Size	Gross area
US single roll	20.5 in x 16.5 ft	About 28 sq ft
US double roll	20.5 in x 33 ft	About 56 sq ft
European roll	53 cm x 10.05 m	About 5.33 m2

Be careful with the coverage figure printed on the label. When a label says a roll covers X square feet, that is its gross area, width multiplied by length, before anything is cut. It is not the usable coverage once drops are trimmed and patterns are matched. A double roll holds twice the paper of a single roll because it is twice as long, not wider, which is why it usually gives you more complete drops and fewer awkward part-rolls left over.

The strip method in five steps

Step 1: Measure the perimeter

Measure the length and width of the room at floor level and add them together, then double the result. That is the full run of wall you are covering. Measure each wall separately if the room has alcoves, a chimney breast or an L shape, and add the pieces together instead of forcing the room into a rectangle.

Step 2: Count the strips

Divide the perimeter by the width of your roll and round up. A 20.5 inch roll covers 20.5 inches of wall with each strip, no more, so any fraction of a strip still needs a whole strip cut for it. This is the step the area method skips, and it is why area estimates so often come up short.

Step 3: Work out the drop

Your drop is the ceiling height plus a trim allowance of 4 inches (10 cm), which lets you trim neatly at the ceiling and the skirting. If the paper has a pattern repeat, round the drop up to the next whole multiple of that repeat, so the pattern lines up across neighbouring strips. That rounding is explained in full in our guide to wallpaper pattern repeat, and it can change your roll count more than any other single number.

Step 4: Count drops per roll

Divide the roll length by your drop and round down. Only complete drops count. A leftover piece that is shorter than a full drop may be useful above a door or below a window, but it cannot cover a full-height section of wall, so never count it as a drop when you are ordering.

Step 5: Turn strips into rolls

Divide the number of strips by the drops per roll and round up. That is your order quantity before any deduction for doors and windows. You can check every stage in seconds with the wallpaper calculator, which follows exactly these five steps and shows its strips and drops as well as its final roll count.

Worked example: a 12 x 10 ft room

Take a room that measures 12 ft by 10 ft, with an 8 ft ceiling, and a US double roll with no pattern repeat. The perimeter is 2 x (12 + 10) = 44 ft. A double roll is 20.5 inches wide, which is about 1.71 ft, so the room needs 44 divided by 1.71, which rounds up to 26 strips. The drop is 8 ft plus 4 inches of trim, so 8 ft 4 in. A 33 ft roll divided by 8 ft 4 in gives 3 full drops per roll, with a short leftover. Rolls = 26 divided by 3, rounded up, which is 9 rolls.

Now allow for the openings in that same room. Deducting one standard door and one standard window brings the requirement down to 8 rolls. That one-roll difference is the honest value of the deduction: real, but modest, because most of the wall around and above those openings still needs paper.

Doors and windows

As a working rule, deduct roughly 3 ft of wall for each standard door and each standard window. That is about the width of wall that does not need a full-height strip. Resist the temptation to deduct more. You still hang wallpaper above doors and above and below windows, and those short pieces are normally cut from offcuts and from the leftover ends of rolls. If you deduct the full area of a large window as if that wall had vanished, you will order too little and discover it on the last wall. Small rooms with one door and one window are exactly where over-deducting hurts most, because there are fewer spare strips to rescue you. When in doubt, deduct the standard amount, run the numbers through the wallpaper calculator, and keep the spare roll described below.

Buying rules that prevent a ruined job

First, check that every roll carries the same batch or dye-lot number. Wallpaper is printed in runs, and colour can shift slightly between runs in a way that is invisible in the shop and obvious on the wall. Second, order everything at once. Going back for one more roll a week later is how mismatched batches happen. Third, keep one spare roll for repairs. A damaged section replaced from the same batch disappears; a section replaced from a later printing often does not. Fourth, keep the label. It records the pattern number, batch and repeat you will need if you ever order again, and a photograph of it on your phone takes ten seconds. Finally, unroll and inspect each roll before you cut it, and if you are new to hanging, read our wallpaper pattern repeat guide before the first drop, not after the third.

Frequently asked questions