Wallpaper Calculator
Work out how many rolls of wallpaper to buy for a whole room or a single accent wall. The calculator subtracts doors and windows and allows for pattern matching.
- Wall area
- 333 sq ft
- Usable coverage per roll
- 47.6 sq ft
How this calculator works
Wall area is the room perimeter multiplied by the wall height, minus about 21 sq ft per door and 15 sq ft per window.
Not all of a roll ends up on the wall: patterns must line up from strip to strip and the ends are trimmed. The extra percentage reduces the usable coverage of each roll.
The wall area is divided by the usable coverage per roll and rounded up. In the US, wallpaper is usually sold as double rolls of about 56 sq ft.
Example: a 12 × 12 ft room with 8 ft walls
- Wall area: 2 × (12 + 12) × 8 = 384 sq ft.
- Subtract 1 door and 2 windows: 384 − 21 − 30 = 333 sq ft.
- Usable coverage of a 56 sq ft double roll with 15% for pattern: 47.6 sq ft.
- Rolls: 333 ÷ 47.6 = 7.0, so buy 7 double rolls.
Quick reference
| Room size | Wall area | Double rolls |
|---|---|---|
| 10 × 10 ft | 269 sq ft | 6 |
| 12 × 12 ft | 333 sq ft | 7 |
| 12 × 16 ft | 397 sq ft | 9 |
Tips before you buy
- Check the pattern repeat on the label. Large repeats (over 18 inches) can need 20–25% extra.
- Buy every roll from the same batch (dye lot) — shades can differ between batches.
- Keep one spare roll for future repairs.
Frequently asked questions
How many rolls of wallpaper do I need for a 12 × 12 room?
With 8 ft walls, one door and two windows, a 12 × 12 ft room has about 333 sq ft of wall. That is about 7 double rolls allowing 15% for pattern matching.
How much does a roll of wallpaper cover?
A US double roll covers about 56 sq ft and a single roll about 28 sq ft. After trimming and pattern matching, plan on roughly 45–50 sq ft of usable coverage per double roll.
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Last updated October 25, 2026