Wallpaper calculator
Counts full-height strips around the room, then how many strips each roll yields after pattern repeat and trimming. This is how paperhangers estimate, and it is more accurate than dividing by square feet.
Materials takeoff
Wallpaper Calculator · https://estimahome.com/wallpaper-calculator/
Room length: 12 ftRoom width: 12 ftWall height: 8 ftWidth of openings to skip: 3 ft
- Wall run
- 45 ft
- Strips
- 27
- Strip length
- 100 in
- Strips per roll
- 3
| No. | Item | Qty | Unit | Unit cost | Amount |
|---|---|---|---|---|---|
| 1 | Wallpaper, 20.5 in × 33 ft | 9 | roll | $60.00 | $540.00 |
| 2 | Smoother, knife, seam roller | 1 | set | $20.00 | $20.00 |
- Subtotal
- $560.00
- Likely range
- $476.00 – $644.00
- Order every roll from the same batch (dye lot) number, plus one spare for repairs.
- If strips per roll is 0, the roll is shorter than one strip: check roll length and wall height.
Buy these materials
- 9 rolls of wallpaperAmazon search for rolls of wallpaper (opens in new tab)
- 1 wallpaper tool kitAmazon search for wallpaper tool kit (opens in new tab)
Links open a store search for each item. Check sizes and grades against your plan.
Quick reference
- A standard US double roll is 20.5 in × 33 ft, about 56 sq ft.
- With 8 ft walls and no pattern repeat, one double roll gives 3 full strips.
- Rolls = strips needed ÷ strips per roll, rounded up.
How it's calculated
⌈x⌉ means round up to the next whole unit; ⌊x⌋ means round down. Every quantity you buy is rounded up.
Strips = ⌈ (2 × (length + width) − openings) × 12 ÷ roll width ⌉Strip length = wall height × 12 + pattern repeat + trimStrips per roll = ⌊ roll length × 12 ÷ strip length ⌋Rolls = ⌈ strips ÷ strips per roll ⌉Cost = Σ (quantity × unit price); range = cost × (1 ± range % ÷ 100)
Worked example
A 12 × 12 ft room has 48 ft of wall. Skipping 3 ft for a door leaves 45 ft, or 540 in. At 20.5 in per strip that is 27 strips. Each strip is 96 in of wall plus 0 in repeat plus 4 in trim = 100 in. A 33 ft roll is 396 in, so it yields 3 strips. 27 ÷ 3 rounds up to 9 rolls. At the default prices: $560.00.
Questions
How do I account for pattern repeat?
Add the repeat length to each strip, as this calculator does. On 9 ft walls, a 21 in repeat drops a standard double roll from 3 strips to 2.
Do I subtract windows?
Usually not. You still need full strips above and below, and the offcuts rarely fit elsewhere. Subtract doors and wide openings that run close to full height.
Single roll or double roll?
Many US papers are priced per single roll but sold only in double rolls. Check the label before comparing prices.
Cite: “Wallpaper Calculator.” EstimaHome, https://estimahome.com/wallpaper-calculator/. Updated 2026-10-20. Formulas in machine-readable form: /api/calculators.json.