Wallpaper Calculator
Find out how many rolls of wallpaper you need to cover a room’s walls, based on its dimensions and your wallpaper’s coverage per roll.
What this calculator does
The wallpaper calculator estimates how many rolls of wallpaper you need to cover a room’s walls, after subtracting window and door openings.
The formula
Gross wall area is the room’s perimeter (2 x length + width) multiplied by wall height. Subtracting the combined area of windows and doors gives the net area that needs to be papered. Dividing by your wallpaper’s usable coverage per roll — commonly around 56 square feet for a standard U.S. double roll after accounting for pattern matching and trimming waste — and rounding up gives the number of rolls to buy.
Coverage varies by pattern repeat: large, complex repeats waste more paper than small or random patterns. Check your specific product’s coverage rating and consider ordering one extra roll from the same dye lot for future repairs.