Wallpaper calculator
How many rolls of wallpaper a room needs, counted strip by strip so the pattern repeat is included.
- Strip length
- Strips per roll
- Wall area
Defaults are a typical US double roll (about 20.5 in × 33 ft). Use the width and length on your roll's label.
How to use it
Enter the room's length, width and wall height in feet. Then copy the roll width, roll length and pattern repeat from the wallpaper's label. The calculator works out how many full-height strips go around the room, how many strips you get from each roll, and the number of rolls to buy.
Check whether the paper is sold as single or double rolls. Prices are often shown per single roll, but most US wallpaper is packaged as double rolls. Entering the wrong one halves or doubles the answer.
How it's calculated
- Strip length = wall height + pattern repeat + 4 in for trimming at the top and bottom.
- Strips per roll = roll length ÷ strip length, rounded down: a part strip at the end of a roll can't be used for a full-height drop.
- Strips needed = room perimeter ÷ roll width, rounded up.
- Rolls = strips needed ÷ strips per roll, rounded up.
This strip method is how paperhangers estimate. Simply dividing the wall area by the roll's coverage ignores the offcut at the end of every roll and the pattern matching, so it often comes up short.
| Roll | Typical size | Coverage on the label |
|---|---|---|
| US single roll | about 20.5 in × 16.5 ft | about 28 sq ft |
| US double roll | about 20.5 in × 33 ft | about 56 sq ft |
| European roll | about 21 in × 33 ft (53 cm × 10 m) | about 57 sq ft |
Pattern repeat
The pattern repeat is the distance before the design starts again, printed on the label. A bigger repeat means more paper wasted matching each strip to the one beside it. Random-match paper (repeat 0) wastes the least; large half-drop patterns waste the most.
Tips
- Doors and windows: the calculator counts the full perimeter. Pieces above doors and around windows are cut from leftovers, and the spare covers mistakes.
- Buy one extra roll for future repairs, and make sure every roll has the same batch (dye lot) number. Colors can differ between batches.