Worldwide
Wallpaper calculator
Wallpaper is estimated in strips, the trade word for a single floor-to-ceiling length cut from a roll.
A standard wallpaper roll is about 10.05 m long and 0.53 m wide.
This calculator counts the strips a room needs, sees how many whole strips each roll yields, and turns that into the number of rolls to buy. Enter the perimeter of the room (the distance all the way round the papered walls), the wall height, any pattern repeat, and the roll size, and it returns the rolls to buy, the strips the walls need, the strips you get per roll, and the wall area for reference. A standard roll across the UK and much of Europe is about 10.05 metres long and 0.53 metres wide, which the tool uses as the default, though imported and feature rolls vary, so check the label. The method follows how a decorator works. The number of strips around the room is the perimeter divided by the roll width, rounded up, because each strip covers one roll-width of wall. The strips you get from a roll is the roll length divided by the height of one strip, rounded down, since a part strip left at the end of a roll is usually too short to hang. The catch is the pattern. A plain or random-match paper hangs with almost no waste, but a patterned one has to line up from strip to strip, so you lose up to a full repeat off the top of each length to get the match. This tool adds one repeat to the strip height when you enter a repeat, the safe and common rule. People reach for this before hanging a feature wall or a whole room, when checking a decorator quote, or when a discontinued paper means buying enough in one go matters. Doors and windows are normally left in the perimeter rather than subtracted, because the offcuts above and below them rarely line up to reuse and the spare guards against a torn strip. Buy every roll from the same batch number and keep one back.
How it works
- Measure the room perimeter: add the length of every wall you are papering.
- Enter the wall height and, for a patterned paper, the pattern repeat from the label.
- Set the roll length and width, or keep the standard 10.05 by 0.53 metres.
- The tool divides the perimeter by the roll width for the strips needed, rounded up.
- It divides the roll length by the strip height for strips per roll, then works out the rolls.
rolls = ceil( strips needed / strips per roll )
Strips needed is the room perimeter divided by the roll width, rounded up, because each strip covers one roll-width of wall. Strips per roll is the roll length divided by the height of one strip, rounded down, since a leftover shorter than a full strip cannot be hung. One pattern repeat is added to the strip height when a repeat is entered, to allow for the trim that lines the design up. Dividing the strips needed by the strips per roll and rounding up gives the rolls to buy.
- perimeter
- distance around the papered walls, in metres
- roll width
- width of one strip, about 0.53 m for a standard roll
- strip height
- wall height plus one pattern repeat for matching
- roll length
- length of paper on a roll, about 10.05 m as standard
How a roll behaves
| Standard roll size | 10.05 m by 0.53 m | about 5 m² of paper |
| Strips per roll, 2.4 m walls, plain | 4 strips | 10.05 divided by 2.4 |
| Strips per roll, 2.4 m walls, 0.5 m repeat | 3 strips | a repeat costs a strip |
| Strip width on the wall | 0.53 m each | perimeter divided by this |
Worked example
A room with a 16 metre perimeter, 2.4 metre walls, no pattern repeat, and standard 10.05 by 0.53 metre rolls: each strip is 2.4 m tall, so a roll yields 4 whole strips (10.05 divided by 2.4 is 4.18, rounded down). The walls need 31 strips (16 divided by 0.53 is 30.2, rounded up), and 31 strips at 4 per roll is 8 rolls. Add a 0.5 m pattern repeat and each strip needs 2.9 m, dropping the roll to 3 strips and pushing the same room to 11 rolls. The repeat is what makes a patterned paper cost more.
Key facts
- Wallpaper is counted in strips, one floor-to-ceiling length per roll width.
- A standard roll is about 10.05 m long and 0.53 m wide.
- A pattern repeat trims usable length, so patterned papers need more rolls.
- Doors and windows are normally left in, since the offcuts rarely reuse.
Tips
- Measure the tallest wall height and cut all strips to that, trimming at the bottom.
- Buy every roll in one go with the same batch number, plus one spare.
- For a feature wall, use just that wall width as the perimeter.
- Check the label for the repeat and roll size before trusting any default.
Frequently asked questions
What is a strip or drop?+
It is one length of wallpaper hung from ceiling to skirting, the width of the roll. Decorators call it a drop. The whole job is counted in strips: how many the walls need, and how many you can cut from each roll. Thinking in strips is what makes a wallpaper estimate accurate, since rolls are rarely used without some offcut.
Do I subtract doors and windows?+
Usually no. The offcuts of paper above and below a door or window are short and rarely line up to reuse on the next wall, especially with a pattern, so leaving the openings in the perimeter gives a safe figure and a little spare. Only subtract for a very large opening like patio doors or a wide picture window.
How does a pattern repeat change the count?+
A patterned paper has to match from strip to strip, so you trim up to a full repeat off the top of each length to line the design up. That shortens the usable paper per strip and means fewer strips per roll. The tool adds one repeat to the strip height when you enter a repeat, the standard safe allowance.
What size is a standard roll?+
A standard roll is about 10.05 metres long and 0.53 metres wide, the common size in the UK and much of Europe, giving roughly 5 square metres of paper. American and some designer rolls differ in both length and width, so always check the label and enter the real figures rather than assuming the default.
Why buy from the same batch?+
Wallpaper is printed in batches, and the shade can vary slightly between them, enough to show as a faint stripe where two batches meet on a wall. Every roll carries a batch or shade number; buying them together, plus one spare, means they all match. A roll bought later from a different batch may not.
How do I measure the perimeter?+
Add the length of each wall you intend to paper. For a rectangular room that is two times the length plus two times the width. If you are papering only a feature wall, use just that wall width as the perimeter. The wall height is floor to ceiling at the tallest point, since strips are cut to the longest drop.
Things to watch
- A large pattern repeat can add several rolls, so never ignore it on patterned paper.
- Imported and designer rolls vary in size; enter the real label figures.
- Batches differ in shade, so topping up later risks a visible mismatch.
Last updated: 2026
This is an estimate for general guidance, not financial, tax, legal or medical advice. Figures can change and individual circumstances vary. Always confirm with an official source before making decisions.
Built and maintained by Vikas Dulgunde. Editorial standards.