Free tool
Enter your walls, roll size and pattern repeat and get drops, rolls to order, paste and cost — for US double rolls, EU/UK rolls and wide formats.
How it works
Wall area = total wall width × height, minus about 21 sq ft (1.9 m²) per door and 15 sq ft (1.4 m²) per window. Dividing by the wall height turns that into the width of wall you actually cover, and dividing by the roll width gives the drops (full-height strips) you need — plus 10% for trimming and mistakes.
Each drop is cut to the wall height plus 4 in (10 cm) for trimming. With a straight match the drop is rounded up to a whole number of pattern repeats; with a drop match half a repeat is added first, because alternate strips shift by half a pattern. Drops per roll = roll length ÷ drop length, rounded down; rolls = drops needed ÷ drops per roll, rounded up. We always suggest one spare roll from the same batch number.
Paste is estimated at about 200 g of ready-mixed adhesive per square meter (one 5 kg tub per 25 m²); paste-the-wall papers use a little less. Thinking of a full color drench instead? See the color drenching guide.
FAQ
A 12 × 12 ft room with 8 ft ceilings has about 384 sq ft of wall before openings — around 330 sq ft after a door and two windows. With standard US double rolls (about 56 sq ft each) and a 21 in straight-match repeat you typically need 9 rolls, plus one spare — the repeat stretches each drop to about 105 in, so only three drops fit on a roll.
In the US wallpaper is priced by the single roll but almost always sold as a double roll, which is twice the length (usually 20.5 in × 33 ft). Check whether the price you see is per single or double roll before you multiply.
The pattern on one strip lines up half a repeat lower than on the strip beside it, so every other strip is offset. It hides the join well but wastes more paper — add half a repeat to each drop, which this calculator does automatically.
Yes. Buy at least one more roll than the calculation, from the same batch (dye lot) number. Colors vary slightly between batches, and a spare roll makes future repairs invisible.
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