Wallpaper Calculator (Rolls per Room)
Estimate how many rolls of wallpaper you need for a room, including a waste allowance for pattern match and trimming. Works with US double rolls and European standard rolls.
Last updated: September 2026
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About this calculator
The formula is R = ceil((A × (1 + W)) / C), where R is the roll count, A is the wall area to cover, W is the waste factor (decimal), and C is the usable coverage of a single roll.
Roll coverage is quoted differently depending on where you shop. In the US, wallpaper is often sold in 'double rolls' that cover about 50–56 sq ft; single rolls in the same lineup cover about 25–28 sq ft. In Europe, a standard roll (10.05 m × 0.53 m) covers roughly 57 sq ft (5.3 m²). Always check the roll's own coverage number before ordering.
Waste allowance matters more with patterned paper than solid colors. Small pattern repeats (under 6 inches) need about 10% waste. Half-drop and large repeats (18–22 inches) commonly need 20–25% waste. Grasscloth and natural materials have irregular repeats and need extra tolerance for shading; buy 25–30% extra so all rolls come from the same production batch (‘run’ or ‘lot’ number).
Always buy an extra roll beyond the calculation. Later touch-ups from a different batch will not match, and returning a single unopened roll is usually straightforward at big-box retailers. Keep the roll and record the SKU + lot number for future repairs.
How to use
Example — a 12 × 14 ft dining room, 8 ft ceilings, 15% waste, US single rolls (≈25 sq ft each). Wall area ≈ (12 + 14) × 2 × 8 = 416 sq ft, minus 40 sq ft for a doorway and window → 376 sq ft. R = ceil((376 × 1.15) / 25) = ceil(432/25) = ceil(17.3) = 18 single rolls (9 double rolls in US pricing). Add one extra for touch-ups → order 10 double rolls. Example — a European bedroom with a large-repeat pattern. Room walls = 30 m² ≈ 323 sq ft. Large repeat needs 25% waste. European standard roll covers about 57 sq ft. R = ceil((323 × 1.25) / 57) = ceil(404/57) = ceil(7.08) = 8 rolls. Order 9 to have one spare. Cross-check with the paint-calculator at /en/calculators/construction/paint-calculator/ if you're also painting the ceiling.
Frequently asked questions
What's the difference between a single and double roll?
In the US, wallpaper is often priced by single roll but packaged as double rolls (a single continuous strip that would have been two singles laid end-to-end). A double roll is easier to hang because you get more full-height drops from one continuous piece with less waste. When calculating, use single-roll coverage (≈25 sq ft) for the math and remember to divide the answer by 2 to get double rolls for ordering. This calculator's default 25 sq ft/roll is the US single-roll value; if you enter 56, you'll get double rolls.
How much waste allowance should I use?
Depends on the pattern repeat. Small repeats (under 6 inches) or non-directional patterns: 10%. Medium repeats (6–18 inches): 15%. Large repeats (18+ inches): 20–25%. Half-drop patterns need an extra 5% because alternate strips shift. Grasscloth or natural materials: 25–30% waste plus buy an extra roll for batch matching. Solid colors and textures with no pattern: 5–10% is enough.
Why does the batch (lot) number matter?
Wallpaper is printed in production runs, and slight color variations between batches are common — they can be invisible at the roll but obvious once two batches are hung next to each other on the same wall. Order all rolls from the same lot number, and buy one extra for touch-ups. If a manufacturer no longer has your lot, they'll usually offer to reprint a matching batch for larger orders.
Should I hire a pro?
Wallpaper is significantly harder to hang than paint, especially with patterns. Vinyl and pre-pasted papers are the easiest for a DIYer; grasscloth, silk, and hand-blocked papers are best left to a professional installer. Rule of thumb: if the material costs more per roll than the labor to hang it, hire the pro. A typical professional wallpaper installation in the US runs $50–100 per roll installed on top of material cost.