Wallpaper calculator: how many rolls?
Count strips, not square feet. Wall width ÷ roll width gives the strips; each is cut to the wall height plus 4 in, rounded up to whole pattern repeats. A 12 ft wide, 8 ft high wall with a 21 in repeat needs 8 strips, 3 per US double roll: 3 rolls.
Updated · By the Interior Redesign AI editorial team · Sources cited on the page
Assumptions: 4 in (about 2 in top and bottom) of trim per strip, and half a repeat extra per strip for half-drop patterns.
Rolls to buy
3 rolls
8 strips, 3 per roll.
| Roll | 20.5 in × 33 ft |
|---|---|
| Strips across the walls | 8 |
| Cut length per strip | 105 in |
| Strips per roll | 3 |
| Rolls by plain area (undercounts) | 2 |
| Rolls to buy | 3 |
- OKWall area 96 sq ft. Buy every roll from the same batch so the color matches.
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Key numbers
- US double roll
- about 20.5 in × 33 ft, about 56 sq ft (York Wallcoverings listing)
- European roll
- 52 cm × 10 m, about 5.2 m² (Graham & Brown listing)
- Strips per wall
- wall width ÷ roll width, rounded up
- Strip length
- wall height + 4 in trim allowance, rounded up to whole repeats (our assumption)
- Half-drop match
- add half a repeat per strip (our assumption)
- Area method
- wall area ÷ roll area usually undercounts once you add trimming and the repeat
Worked example
An accent wall, 12 ft wide and 8 ft high
US double roll, 21 in pattern repeat, straight match.
- Strips: 12 ft × 12 = 144 in ÷ 20.5 in = 7.02 → 8 strips.
- Strip length: 96 + 4 = 100 in, rounded up to 5 repeats of 21 in = 105 in.
- Per roll: 33 ft × 12 = 396 in ÷ 105 = 3 strips.
- Rolls: 8 ÷ 3 → 3 double rolls (the plain area method would say 2).
Buy 3 double rolls for this wall, from the same batch.
How we calculate
Wallpaper is hung in vertical strips, so we count strips. Strips needed = wall width ÷ roll width, rounded up. Each strip is cut to the wall height plus a trim allowance, then rounded up to a whole number of pattern repeats so the design lines up from strip to strip. Strips per roll = roll length ÷ strip length, rounded down; rolls = strips ÷ strips per roll, rounded up.
Roll sizes come from maker listings: a York double roll is about 20.5 in by 33 ft, and a Graham & Brown roll is 52 cm by 10 m. Always check the label of the paper you buy, including its pattern repeat and match type.
Assumptions: a 4 in trim allowance (about 2 in at the ceiling and 2 in at the baseboard) and an extra half repeat per strip for half-drop patterns. We do not subtract ordinary doors and windows, since the strips above and below them still use most of a length; enter only large openings, such as a slider, to skip. Buy all rolls from one batch (dye lot) and consider one spare.
Estimates, sources
Planning estimates and published guidelines, not quotes, designs or code rulings. Figures were checked on each source on the date shown. Local prices, your home and your jurisdiction's adopted code decide the real answer.
- Charm wallpaper (double roll specification) (York Wallcoverings, as of Oct 26, 2026): double roll approximately 20.5 in wide × 33 ft long, about 56.4 sq ft (the same size appears across York's listings; some collections are 27 in × 27 ft, about 60.8 sq ft). Read from York's site listings; direct page fetches were rate-limited
- Graham & Brown Jardin Botanico wallpaper, Sage (John Lewis (retailer listing), as of Oct 26, 2026): roll L10m × 52 cm, approximate coverage 5.2 m², pattern repeat 75 cm, half-drop match
Wallpaper rolls by wall size
A whole 12 × 14 ft room, 8 ft high, minus a 3 ft doorway, with a 21 in half-drop repeat, takes 29 strips at 3 per roll: 10 US double rolls.
| Wall width | No repeat | 21 in straight | 21 in half-drop |
|---|---|---|---|
| 8 ft | 2 | 2 | 2 |
| 12 ft | 3 | 3 | 3 |
| 16 ft | 4 | 4 | 4 |
| 24 ft | 5 | 5 | 5 |
| 52 ft | 11 | 11 | 11 |
US double rolls vs European rolls
The two common roll formats are close in area: US double roll (20.5 in × 33 ft) and European roll (52 cm × 10 m). Listings can quote price and coverage per single or per double roll, so check which before you compare papers.
How to use this tool
Measure the walls
Total width of the walls to paper and the height from baseboard to ceiling.
Pick the roll
US double roll, European roll, or enter the width and length from the label.
Enter the repeat
Pattern repeat and straight or half-drop match, from the label; 0 for a random match.
Read the rolls
Strips, strips per roll and rolls to buy, then add a spare if the pattern is busy.
Questions
How many rolls of wallpaper do I need for an accent wall?
A 12 ft wide, 8 ft high wall takes 3 US double rolls with a 21 in repeat. Without a repeat it is 3.
How much does pattern repeat add?
Each strip rounds up to a whole number of repeats, so a large repeat can waste up to nearly one repeat per strip. On a 33 ft US double roll it costs a strip only when the rounded-up cut passes a third of the roll: on 8 ft walls a 21 in repeat still gets 3 strips per roll, but on a 10.5 ft wall it drops from 3 strips per roll to 2.
What is a half-drop match?
The pattern on each strip sits half a repeat lower than the strip before. It wastes more than a straight match; we add half a repeat per strip.
Should I subtract windows and doors?
Usually not for normal doors and windows: the strips above and below them still use most of a length. Only skip large openings such as a slider.
How big is a roll of wallpaper?
A US double roll is about 20.5 in by 33 ft (about 56 sq ft). A European roll is 52 cm by 10 m (5.2 m²). Check your paper's label.
Should I buy an extra roll?
For a busy pattern or a big job, one spare is cheap insurance. Rolls from a later batch can differ slightly in color, so buy them together.
Numbers done. Now see it.
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