How to use this wallpaper calculator
- Measure the room and wall height.
- Count doors and windows.
- Choose the roll type printed on the label.
- Pick the pattern size to add extra for matching.
Example
A 12 × 12 ft room with 8 ft walls, one door and one window has 348 sq ft (32.3 m²) of wall. With a medium pattern repeat (15% extra) and US double rolls, you need 8 rolls.
What to know before you buy
Understanding pattern repeat
The pattern repeat is the vertical distance before the design repeats, printed on the label. A straight match lines up across strips at the same height; a drop match shifts by half a repeat. Large and drop-match repeats waste more of each roll.
Peel-and-stick or traditional
Peel-and-stick wallpaper is easy to remove and good for renters and accent walls. Traditional paste-the-wall or pre-pasted papers are more durable and usually cheaper per square foot for whole rooms.
US double rolls for a room with 8 ft walls (1 door, 1 window, plain paper)
| Room size | Rolls needed | Wall area |
|---|---|---|
| 10 × 10 ft | 6 | 284 sq ft (26.4 m²) |
| 10 × 12 ft | 7 | 316 sq ft (29.4 m²) |
| 12 × 12 ft | 7 | 348 sq ft (32.3 m²) |
| 12 × 15 ft | 8 | 396 sq ft (36.8 m²) |
| 14 × 16 ft | 9 | 444 sq ft (41.3 m²) |
Formula
Rolls = (wall area − openings) × (1 + pattern allowance) ÷ usable area per roll.
Tips from the pros
- Check the batch (lot) number on every roll: shades vary between batches.
- Start hanging in the least visible corner, because the pattern will not match where you finish.
- Prime walls with a wallpaper primer so the paper can be removed later.
Common mistakes to avoid
- Ignoring the pattern repeat: large repeats can waste a lot of each roll.
- Mixing up single and double rolls when comparing prices.
Frequently asked questions
How much extra wallpaper should I buy?
About 10% for plain papers and 15–20% for large pattern repeats, and buy all rolls from the same batch.
What is a double roll?
In the US wallpaper is priced by single roll but sold in double rolls, which cover about 56 usable square feet.
How many rolls of wallpaper for a 12x12 room?
With 8 ft walls, one door and one window, about 7 US double rolls with a 10% allowance; more for large pattern repeats.
How much does a roll of wallpaper cover?
A US double roll covers about 56 usable sq ft; a standard European roll (10.05 × 0.53 m) covers about 5.3 m² (57 sq ft) before pattern matching.