Wallpaper Calculator
Your estimate
- Drops per roll
- 4
- Area
- 334 ft²37.11 yd² · 31.03 m²
Counts full-height drops per roll, so pattern repeat and ceiling height are taken into account.
Updated 2026-10-20 · Based on: coverage figures from paint and drywall makers (USG).
How to use the Wallpaper Calculator
- Enter the room size and wall height.
- Enter doors and windows.
- Pick the roll size and the pattern repeat printed on the label.
- Buy all rolls from the same batch number.
Formula
Drops needed = net wall width ÷ roll width. Drops per roll = roll length ÷ (wall height + pattern repeat + 2 in trim).
Rolls = drops needed ÷ drops per roll, rounded up.
Worked example
With the values preset in the calculator above:
- Length
- 12 ft
- Width
- 12 ft
- Height
- 8 ft
- Doors
- 1
- Windows
- 2
- Roll size
- Double roll 20.5 in × 33 ft
- Pattern repeat
- 0 in
- Extra for waste
- 0 %
- Rolls
- 7
- Drops needed
- 25
- Drops per roll
- 4
- Area
- 334 ft² (37.11 yd²)
Frequently asked questions
How many rolls of wallpaper for a 12 × 12 room?
With 8 ft walls, one door and two windows: about 7 double rolls of 20.5 in × 33 ft.
What is a double roll?
US wallpaper is priced by the single roll but sold in double rolls (about 56 ft²). European rolls are 0.53 × 10.05 m (5.3 m²).
How does pattern repeat change the amount?
Each drop must start at the same point of the pattern, so a large repeat wastes paper on every drop — up to one fewer drop per roll.
More calculators
Estimates only — check quantities with your supplier and local building code before you order.