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Wallpaper Calculator

Enter the total width and height of the walls you are papering to find how many rolls to buy. Set the roll width and length from the label, subtract doors and windows, and add an allowance for matching the pattern.

Quick examples

Add the widths of every wall you are papering (the room perimeter for a full room).

Each door subtracts 21 sq ft.

Each window subtracts 15 sq ft.

A US double roll is typically 20.5 in × 33 ft; check the label.

%

Use 10% for plain papers, 15–25% for large pattern repeats.

$
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Rolls needed8
Wall area to cover
365 ft²
Coverage per roll
56.37 ft²
Wallpaper cost
$320.00

Saved setups

Save a set of inputs you reuse — your usual rate, your loan, your room sizes — and load it back in one tap.

    Your recent calculations

    Results you calculate here are kept on this device so you can come back to them.

      Formula

      Wall area = total wall width × height − doors × 21 − windows × 15 (sq ft)
      Coverage per roll = roll width × roll length
      Rolls = wall area × (1 + waste %) ÷ coverage per roll, rounded up

      How to use it

      1. Add up the widths of the walls to cover and enter the total.
      2. Enter the wall height and the number of doors and windows.
      3. Enter the roll width and length shown on the label.
      4. Raise the waste allowance for large pattern repeats.

      Worked examples

      A 14 × 12 ft room (52 ft of wall) with 8 ft ceilings, one door and two windows

      Wall area to cover
      365 ft²
      Coverage per roll
      56.37 ft²
      Rolls needed
      8
      Wallpaper cost
      $320.00

      A 12 ft wide accent wall, 8 ft high

      Wall area to cover
      96 ft²
      Rolls needed
      2
      Wallpaper cost
      $80.00

      Roll sizes

      In the US, wallpaper is usually priced per single roll but packaged as a double roll, commonly 20.5 in wide by 33 ft long, about 56 sq ft. European rolls are typically 52 cm × 10 m, about 5.2 m². Enter the actual bolt you will receive.

      Check that every roll carries the same batch or dye-lot number. Color can shift noticeably between print runs.

      Pattern repeat

      Each strip has to start at the same point in the pattern, so the larger the repeat, the more is trimmed off every strip. Allow about 10% for plain or random-match papers, 15% for small repeats and 20–25% for repeats over 18 in or drop-match patterns.

      Questions people ask

      How many rolls of wallpaper do I need for a 12×14 room?

      The room has 52 ft of wall. With 8 ft ceilings, one door and two windows that is 365 sq ft. With 15% waste and 56.4 sq ft double rolls, you need 8 rolls.

      How much wallpaper for one accent wall?

      A 12 ft wide, 8 ft high wall is 96 sq ft. With 15% waste that takes 2 double rolls of 20.5 in × 33 ft.

      How many square feet does a roll of wallpaper cover?

      A standard US double roll (20.5 in × 33 ft) covers about 56 sq ft before trimming, and roughly 50 sq ft of usable coverage once pattern matching is allowed for.

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