This wallpaper calculator works out how many rolls a room needs: wall area from your room’s dimensions, minus doors and windows, divided by a roll’s real usable coverage — pattern matching included.
The Roll Math, Honestly
Wallpaper is sold by the roll but spent by the strip. A US single roll holds ~56 sq ft of paper, yet after cutting ceiling-height strips and sliding them to match the pattern, only ~28–30 sq ft lands on the wall — the famous coverage on the label already knows this. This calculator uses 28 sq ft as its default usable figure and lets you change it (European rolls at 56–60 sq ft gross are similar after matching; large-repeat patterns drop toward 25). Walls painted instead? Our Paint Calculator handles that version. Part of our Construction Calculators collection.
Worked Example (Verified)
A 12 × 10 ft room, 8 ft ceiling, 2 doors, 1 window:
- Perimeter: 2 × (12 + 10) = 44 ft → gross wall area 44 × 8 = 352 sq ft
- Minus openings: 2 × 21 + 1 × 12 = 54 → 298 sq ft
- Rolls: 298 ÷ 28 = 10.6 → 11 rolls (always round up; a roll cannot be bought in fractions)
Before You Order
- Dye lot is destiny: all rolls for a job must share a lot/batch number — color shifts between lots are invisible in the store and obvious on the wall.
- Pattern repeat drives waste: a 24″ repeat can consume a quarter of every strip. If your paper has a big dramatic repeat, lower the coverage input to 24–25.
- Accent wall only? Enter its length as the room “length” and width 0 — or simply divide: one 12-ft wall at 8 ft high is 96 sq ft ≈ 4 rolls.
- Ceilings, stairwells (long drops), and bay windows break the rectangle assumption — measure those drops individually and add them as extra square footage in your head-check against the result.
Related Tools
- Paint Calculator — the painted-wall alternative
- Construction Calculators — the full collection
Frequently Asked Questions
How many rolls of wallpaper do I need for a 12×10 room?
About 11 US single rolls for 8 ft ceilings with typical doors and windows: 352 sq ft gross walls become ~298 sq ft net, at ~28 sq ft of usable coverage per roll.
How much area does one roll of wallpaper cover?
Nominally ~56 sq ft (US single roll), usefully ~28–30 sq ft after cutting and pattern matching — the figure this calculator defaults to. Large repeats waste more.
Should I deduct doors and windows?
Yes for standard sizes (the calculator deducts 21 sq ft per door, 12 per window). The paper over an opening is not truly saved — it becomes off-cuts — but as an area estimate the deduction lands right in practice.
Why buy an extra roll?
Insurance. A torn strip, a mis-measured drop or a future repair all need paper from the same dye lot, which cannot be reordered once the lot sells through. One spare roll is the cheapest policy in decorating.
Does pattern repeat really change the count?
Dramatically. Matching a 24″ repeat can drop usable coverage from 28 to ~24 sq ft per roll — on the example room that is the difference between 11 and 13 rolls. Adjust the coverage input for big repeats.
Is this wallpaper calculator free?
Yes — free, instant, no sign-up.