A 4 × 3.5 m room with 2.4 m high walls needs about 8 standard rolls of plain or small-patterned wallpaper. With a large pattern repeat it needs about 10 rolls. In the US, a 12 × 12 ft room with 8 ft walls needs about 8 double rolls.
Wallpaper isn’t worked out from the wall area alone. You count how many full-height strips (“drops”) you need, and how many of those you can cut from each roll. This is the method decorators use, and it stops you running short halfway round the room.
Quick answer: rolls by room size
These figures are for standard rolls of 10.05 m × 0.53 m, 2.4 m wall height, no large pattern repeat, and doors and windows not deducted.
| Room size | Perimeter | Drops needed | Rolls |
|---|---|---|---|
| 3 × 3 m | 12 m | 23 | 6 |
| 3 × 4 m | 14 m | 27 | 7 |
| 4 × 3.5 m | 15 m | 29 | 8 |
| 4 × 4 m | 16 m | 31 | 8 |
| 4 × 5 m | 18 m | 34 | 9 |
| 5 × 5 m | 20 m | 38 | 10 |
The 10.05 m × 0.53 m roll is the standard size in the UK and Europe, and you will also find it in Australia and Canada. A roll covers about 5.3 m², but you never get all of that onto the wall.
The drop method, step by step
- Measure the perimeter. Add up the length of every wall you are papering.
- Count the drops. Divide the perimeter by the roll width (0.53 m) and round up. A perimeter of 15 m ÷ 0.53 = 28.3, so you need 29 drops.
- Work out the drop length. Take the wall height, add about 10 cm for trimming at the top and bottom, and add one pattern repeat if there is one. Plain paper on a 2.4 m wall gives a drop of 2.5 m.
- Drops per roll. Divide the roll length by the drop length and round down: 10.05 ÷ 2.5 = 4.02, so you get 4 drops per roll. The leftover piece is too short to use.
- Rolls. Divide the drops needed by the drops per roll and round up: 29 ÷ 4 = 7.25, so buy 8 rolls.
The DIYMeter wallpaper calculator runs these steps for you and takes the pattern repeat into account.
What the pattern repeat does to your total
The pattern repeat is printed on the label, often as a number with an arrow, such as 53 cm or 64 cm. Every drop has to start at the same point in the pattern, so you lose part of a repeat with each cut.
Take the same 4 × 3.5 m room with a 64 cm repeat. The drop becomes 2.4 + 0.64 + 0.1 = 3.14 m. Only 3 drops fit in a 10.05 m roll, so you need 29 ÷ 3 = 9.7, which means 10 rolls. That is two more rolls than for plain paper.
In the US: double rolls
In the US, wallpaper is usually priced per single roll but sold in double rolls. A common American double roll is about 20.5 inches wide and 33 ft long, which is around 56 sq ft. Sizes vary between brands, so always check the label.
Worked example (12 × 12 ft room, 8 ft walls):
- Perimeter = 48 ft = 576 inches. 576 ÷ 20.5 = 28.1, so you need 29 drops.
- Drop length = 96 in + 3 in trim = 99 in. A double roll of 396 in gives 4 drops.
- 29 ÷ 4 = 7.25, so buy 8 double rolls. With a 21 in pattern repeat you only get 3 drops per roll, so you need 10 double rolls.
Doors and windows
Most decorators don’t take doors and windows off the total. You still need short pieces above and below them, and the spare paper covers mistakes. If a room has several large windows or a wide patio door, you can take off about half a roll for each one.
Before you buy
- Check the batch number. Every roll should have the same batch (lot) number. Colours vary slightly from one print run to the next, and the difference shows on the wall.
- Buy one spare roll. It covers a cutting mistake, and you will have a matching piece for repairs later.
- Feature wall only? Measure the width of that one wall and use the same drop method. A 3.5 m wall at 2.4 m high needs 7 drops, which is 2 rolls of plain paper.
FAQs
How many square metres does a roll of wallpaper cover? A standard roll is about 5.3 m². Once you allow for trimming and matching the pattern, plan on getting about 4.5 to 5 m² onto the wall.
Do I need lining paper? On old, uneven or freshly plastered walls, lining paper gives a smoother finish and helps the wallpaper stick. Use the same drop method to work out how much you need.
Should I paper the ceiling too? Ceilings are hard work and are usually just painted. If you do want to paper one, count the strips across the shortest side of the room.
Related: the DIY Project Budget & Materials Planner turns your measurements into quantities, costs and a shopping list.
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