Wallpaper Calculator

Wallpaper is ordered in strips, not square feet — and pattern repeat quietly changes how many strips a roll yields. This calculator does the strip math the way installers do, for American double rolls, European rolls, grasscloth and custom bolt sizes.
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How to Measure for Wallpaper

1. Width. Measure each wall you are papering and add the widths together, in feet. Measure around the room at one height; do not subtract standard doors and windows.

2. Height. Floor to ceiling at the tallest point, plus trim allowance — the calculator adds 4 inches automatically for trimming top and bottom.

3. Repeat. Find the vertical repeat on the specification sheet (for example 25.25"). Every strip is cut to a whole number of repeats so the pattern aligns across seams — this is where most self-calculated orders come up short.

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Standard Roll Sizes

American papers are usually priced per single roll but shipped as double-roll bolts. Designer brands like Schumacher and Thibaut follow this convention — confirm the unit before comparing quotes.

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Frequently Asked Questions

‍How many rolls of wallpaper do I need for a 12x12 room?
With 8-foot ceilings: about 48 feet of wall → 22 strips → 8 US double rolls with no repeat. A 20" repeat typically pushes it to 11, because each bolt then yields 2 strips instead of 3.

‍Single roll vs double roll?
US paper is priced per single roll but ships as a continuous double-roll bolt. 8 single rolls = 4 bolts. Confirm the unit before you compare prices.

‍Do I subtract doors and windows?
Not for patterned paper — the pieces above and around openings still come from full-length drops. Deduct only for very large openings or plain unmatched papers.

‍How does pattern repeat change the order?
Each strip rounds up to a whole number of repeats. On a 9-foot wall, a 25" repeat turns a 112" cut into 125" — often costing each roll a strip and adding 30–50% to the order. Half-drop matches consume slightly more again.

‍How much extra should I order?
One extra roll minimum, from the same batch number. Batches shift color; attic stock saves the wall after a repair. For grasscloth and hand-prints, add 15–20%.