Short answer: A standard 12×12 room with 8-foot ceilings needs 7 double rolls of wallpaper — 8 if the pattern has a large repeat. The walls total 348 square feet after subtracting one door and one window, and one standard US double roll covers about 56 square feet.
How the wallpaper calculation works
A 12×12 room has a perimeter of 48 feet. Multiply by the 8-foot ceiling height and the walls total 384 square feet. Subtract one standard door (21 sq ft) and one window (15 sq ft) and you get 348 square feet to paper. One double roll covers about 56 square feet, so 348 / 56 = 6.2, rounded up to 7 double rolls. If the pattern has a large repeat, add about 10 to 15% for matching waste — one extra roll, so 8 double rolls.
Wallpaper rolls by room size
| Room | Net wall area | Double rolls | With a large pattern repeat |
|---|---|---|---|
| 10×10 room | 284 sq ft | 6 | 7 |
| 12×12 room | 348 sq ft | 7 | 8 |
| 14×16 room | 444 sq ft | 8 | 9 |
| 12×15 room | 396 sq ft | 8 | 9 |
(All assume 8-foot ceilings with one door and one window subtracted.)
Single rolls vs double rolls
A single roll covers about 28 square feet, so the same 12×12 room needs 13 single rolls (348 / 28 = 12.4, rounded up), or 15 with a large pattern repeat. Most wallpaper sold in the US comes as double rolls, so always check the coverage printed on the label before you buy.
Frequently asked questions
How many rolls of wallpaper do I need for a 12×12 room?
7 double rolls, or 8 if the pattern has a large repeat.
How much does one roll of wallpaper cover?
A standard US double roll covers about 56 square feet and a single roll about 28 square feet. European rolls are different sizes, so always check the coverage on the label.
Do I subtract doors and windows?
Yes. A standard door is 21 square feet and a window is about 15 square feet. Subtracting them keeps you from buying a roll you do not need.
What if my ceilings are 9 feet?
The wall area grows. A 12×12 room with 9-foot ceilings has 432 square feet of wall (48 x 9), minus 36 for the door and window, which is 396 square feet — 8 double rolls, or 9 with a large pattern repeat.
Work out your exact number before you order with our wallpaper calculator.