Wallpaper Calculator

Why this calculator counts strips, not square feet

Dividing wall area by roll area often comes up short, because wallpaper is hung in full-height strips and a leftover piece usually can't be used. A pattern adds more waste, since each strip must start at a matching point. Counting strips includes both effects.

Worked example: a 15 × 12 ft room with 8 ft walls

This uses US double rolls measuring 20.5 in × 33 ft, with a 12 in pattern repeat.

1. Distance around the room: 2 × (15 + 12) = 54 ft, or 648 in.
2. Strips: 648 ÷ 20.5 = 31.6, so you need 32 strips.
3. Strip length: 96 + 12 + 4 = 112 in.
4. Strips per roll: 396 ÷ 112 = 3.5, so you get 3 full strips.
5. Rolls: 32 ÷ 3 = 10.7, so order 11 double rolls.

Check how your roll is sold

This trips up a lot of buyers. In the US, wallpaper is often priced per single roll but sold in double rolls, so a listed price may cover only half of what you receive. European rolls are usually about 53 cm × 10.05 m. Check both the roll size and the pricing unit on the product page.

Understanding pattern match

• Random match: strips can go up in any position, so enter a repeat of 0.
• Straight match: the pattern lines up straight across adjoining strips.
• Drop match: the pattern lines up diagonally, with each second strip shifted down. It can use more paper in practice, so consider ordering an extra roll.

Doors and windows

Small openings rarely save a complete strip, which is why this calculator doesn't subtract them by default. The usual approach is to enter only wide openings, such as patio doors, in the width to skip.

Before you order

• Buy every roll from the same batch or dye lot, shown on the label. Shades can vary between batches.
• Include a spare roll for mistakes and later repairs, particularly with a large pattern.
• Sloped ceilings and stairwells need a measured plan, since strip lengths vary across the wall.

Painting the other walls? The paint calculator handles those.