Wallpaper Rolls Calculator
The worst part of any wallpaper job is running out one roll short — by the time you reorder, the dye lot may not match or the design may even be discontinued. This calculator uses the industry-standard strip-based method (the same formula Graham & Brown, Sanderson and other manufacturers publish): each strip is rounded up to the next pattern repeat, the perimeter is divided by the roll width to get strip count, a waste percentage is added, and the result is rounded up to whole rolls.
Please enter sensible room dimensions, roll specs and a waste percentage.
Rolls to order
10 rolls
Breakdown
- Room perimeter
- —
- Total wall area
- —
- Net papered area
- —
- Strips needed (base + waste)
- —
- Total coverage
- —
Strip-based estimation, the method used by Graham & Brown, Sanderson and other manufacturers: each strip is rounded up to the next pattern repeat. Formula: rolls = ceil(ceil(perimeter ÷ rollWidth) × (1 + waste%) ÷ floor(rollLength ÷ stripLength)). Order one extra roll for future patch repairs.
Formula
rolls = ceil( ceil(perimeter ÷ rollWidth) × (1 + waste%) ÷ floor(rollLength ÷ stripLength) ), where stripLength = ceil(wallHeight ÷ repeat) × repeat
- · European standard rolls are 53 cm × 10.05 m (about 5.3 m² of paper per roll; usable coverage is lower once patterns are aligned).
- · Wide non-woven rolls are typically 70 cm × 10 m; commercial / contract rolls go up to 106 cm × 10 m and save labour on big rooms.
- · Patterns are either straight-match or drop-match — drop-match papers waste more, so the calculator rounds each strip up to the full label repeat (a conservative assumption that works for both match types).
- · Recommended waste: 10 % for plain / small repeats; 15–20 % for large repeats, drop-match designs or rooms with awkward openings.
- · Door / window deductions use a combined-area approximation. In practice strips are trimmed individually, but the rounding up of strips and the waste % cover the difference.
- · Always order at least one extra roll for future patch repairs — dye lots vary between print runs, and a later roll may not match exactly.
- · The formula matches the Graham & Brown, Sanderson and Anaglypta official roll calculators, but everything runs in your browser — no data leaves your device.
Frequently asked
A roll says it covers 5 m² — why does the calculator say I need extra?
Wallpaper is hung in continuous strips — you can't splice off-cuts to make up the difference. A 10.05 m roll only yields 4 usable strips on a 2.5 m wall (4 × 2.5 = 10 m, leaving 5 cm too short for a 5th strip), so each roll truly covers 4 × 2.5 × 0.53 ≈ 5.3 m². Once you add pattern matching — each strip rounded up to the next repeat — a roll with a 32 cm repeat on the same wall yields only 3 strips, dropping useful coverage even further. The strip-based formula here measures that real-world waste exactly, instead of using the over-optimistic "total area ÷ roll area" estimate that gets people in trouble.
How do I use this for peel-and-stick (self-adhesive) wallpaper?
Use it exactly the same way — peel-and-stick rolls are sold with the same width × length labelling (commonly 0.5 m × 5 m or 0.61 m × 5 m), so just enter those numbers. Because peel-and-stick can be re-applied if you miscut, real-world waste is usually 3–5 % lower than for traditional paste-the-wall rolls — drop the waste slider down to 5–7 % if you're comfortable handling the strips. Pattern repeat works the same way, so enter it from the label.
Roughly how many rolls does a typical Hong Kong studio need?
Take a typical Hong Kong studio bedroom: 3 m × 4 m with a 2.5 m ceiling — perimeter 14 m, walls 35 m², roughly 30 m² to cover after 5 m² of door/window deductions. With a plain 53 cm × 10.05 m roll and 10 % waste, you need about 7–8 rolls; with a drop-match design and 15 % waste, that jumps to 9–10. Most Hong Kong wallpaper retailers (Aberdeen Wallpaper, Telford Plaza, the home stores in Kowloon Bay) sell by the roll at HK$200–800 each (and well over HK$1,500 for premium brands), so paying for one extra roll as future-proofing is cheap insurance.
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