Details
Type feet and inches like 12'6" or just 12.5. Everything is saved on this device, so your list is still here in the shop.
About the wallpaper calculator
Wallpaper is not bought by area alone: it is hung in strips from the ceiling to the floor, and each roll gives only a whole number of strips. A bigger pattern repeat means more paper is lost matching the pattern. That is why simple "divide the wall area" guesses usually come up short.
This calculator works the way a paper hanger does. It finds how many strips fit across your walls, how many strips one roll gives at your wall height (with the pattern repeat and some extra to trim), and from that, the number of rolls.
How to use it
- Choose Feet & inches or Metres & cm
- For a whole room: enter its length, width and wall height
- For a single wall: choose One wall and enter its width and height
- Enter the number of doors and windows
- Check the roll width and roll length on the label, and the pattern repeat
- Read the number of rolls — and buy one more from the same batch
How the rolls are worked out
- Strips needed = the width of all the walls ÷ the roll width, rounded up. Doors and windows reduce it.
- Length of one strip = wall height + pattern repeat + about 4 in (10 cm) to trim at the top and bottom.
- Strips per roll = roll length ÷ strip length, rounded down — a piece too short for a full strip is waste.
- Rolls = strips needed ÷ strips per roll, rounded up.
Roll sizes
| Roll | Width | Length | Area |
|---|---|---|---|
| US double roll | 20.5 in | 33 ft | about 56 sq ft |
| US single roll | 20.5 in | 16.5 ft | about 28 sq ft |
| European / UK roll | 53 cm (21 in) | 10.05 m (33 ft) | about 5.3 m² |
| Wide roll | 70 cm (27.5 in) | 10.05 m | about 7 m² |
In the US, wallpaper is often priced per single roll but sold in double rolls — check which one the price means.
Rolls for common rooms
8 ft walls, US double rolls (20.5 in × 33 ft), no pattern repeat, one door and one window:
| Room | Strips | Double rolls |
|---|---|---|
| 10 × 10 ft | 21 | 7 |
| 10 × 12 ft | 24 | 8 |
| 12 × 12 ft | 26 | 9 |
| 12 × 14 ft | 28 | 10 |
| 14 × 16 ft | 33 | 11 |
A large pattern repeat can add one or two rolls.
What the pattern repeat means
- Random match / no repeat (plains, textures, stripes): enter 0. Least waste.
- Straight match: the pattern lines up straight across. Enter the repeat from the label.
- Drop (offset) match: each strip is shifted by half a repeat. Enter the full repeat — it wastes the most paper.
The repeat is printed on the label, often with a symbol: an arrow for straight match, a staggered arrow for drop match.
Frequently asked questions
How many rolls of wallpaper do I need for a 12x12 room?
With 8 ft walls, one door, one window and no pattern repeat: about 9 US double rolls (20.5 in × 33 ft). With a big pattern repeat, plan on 10 or 11.
How many rolls for an accent wall?
Choose One wall. A 12 ft wide, 8 ft high wall needs 8 strips; with 3 strips per double roll that is 3 double rolls.
Why buy an extra roll?
Rolls are printed in batches, and the colour can differ a little between batches. One extra roll with the same batch number covers a mistake now and a repair later. Many shops take back unopened rolls.
Do I subtract doors and windows?
The calculator takes away the wall width they cover. Over and under windows you still need short pieces, so the saving is small — never subtract more than the calculator does.
How do I measure the pattern repeat?
Look on the label, or measure from one point in the pattern to where exactly the same point appears again below it.
Does this work in metres?
Yes — switch to Metres & cm. The default roll is the European 53 cm × 10.05 m.
Good to know
- Your rooms and roll size are saved in this browser for next time
- Press Copy the list to send it to yourself before you go to the shop
- Nothing is sent anywhere — it works in your browser
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- Paint Calculator — paint for the other walls or the ceiling
- Square Footage Calculator — the area of a room
- Tile & Flooring Calculator — tiles or boxes of flooring
- Concrete Calculator — bags for a slab
- Mulch, Soil & Gravel Calculator — for the garden
- Unit Converter — inches, centimetres and more
