How to Calculate Wallpaper Rolls
Dividing wall area by roll area underestimates wallpaper. Counting strips gives the real number. Here is how.
Updated November 1, 2026
Why area alone does not work
Wallpaper goes up in strips that run from ceiling to floor. Each roll produces a whole number of full-height strips, and the leftover piece is usually too short to use. Matching a pattern adds more waste. An estimate based only on square footage can come up one or two rolls short.
Counting strips step by step
- Measure the perimeter. Add the widths of all walls you will paper, and subtract the width of doors and other floor-to-ceiling openings.
- Count strips. Divide the perimeter by the roll width and round up.
- Find the strip length. Take the wall height, add one pattern repeat, and add about 4 in (10 cm) for trimming.
- Strips per roll. Divide the roll length by the strip length and round down.
- Rolls. Divide strips by strips per roll and round up.
Worked example with a repeat
A feature wall 12 ft wide and 9 ft high, with metric rolls 53 cm × 10.05 m and a 64 cm repeat:
- 12 ft is 366 cm. 366 ÷ 53 = 6.9, so 7 strips.
- Strip length: 274 cm wall + 64 cm repeat + 10 cm trim = 348 cm.
- Strips per roll: 1005 ÷ 348 = 2.9, so 2 strips.
- Rolls: 7 ÷ 2 = 3.5, so 4 rolls.
The same wall in a plain paper fits 3 strips per roll and needs only 3 rolls. The repeat costs a whole roll.
Straight match and drop match
With a straight match, the pattern lines up horizontally at the same height on every strip. With a drop match, alternate strips shift down by half the repeat. Drop matches often produce more waste. Random-match and plain papers have no repeat, so you can enter zero.
Roll sizes
| Roll | Width × length | Coverage |
|---|---|---|
| US double roll | 20.5 in × 33 ft | ≈ 56 sq ft |
| US single roll | 20.5 in × 16.5 ft | ≈ 28 sq ft |
| Standard metric roll | 53 cm × 10.05 m | ≈ 5.3 m² |
| Wide roll | 70 cm × 10.05 m | ≈ 7 m² |
Sizes vary by maker, so use the numbers on the label. The wallpaper calculator does the strip count for you.
Do the math for your project: open the wallpaper calculator.
Frequently asked questions
How many strips are in a roll of wallpaper?
On 8 ft walls with no repeat, a US double roll gives 3 full strips and a 10 m metric roll gives 3 or 4, depending on the height. Large repeats reduce that.
Should I buy an extra roll of wallpaper?
Yes. One spare roll from the same batch covers mistakes and later repairs.
Is wallpaper priced per single roll?
In the US it is often priced per single roll but sold in double rolls. Check the listing before comparing prices.