Use this free wallpaper calculator to plan a home-improvement or DIY project from the measurements and product information you already have.
HomeCalc shows the formula behind the result and keeps product-dependent assumptions editable where possible, so the calculator can match the material, package or supplier you actually plan to use.
Calculate paintable wall area, subtract openings, add a cutting allowance and divide by usable roll coverage.
FREE WALLPAPER ESTIMATOR
Wallpaper Calculator: Rolls Needed for a Room
Estimate wallpaper rolls from room dimensions, doors, windows and the usable coverage stated for one roll.
Estimated result
Use usable roll coverage, not just the roll's raw area
Wallpaper is cut into wall-height drops, so the usable coverage of a roll can be lower than its simple length × width area. HomeCalc calculates wall area after openings and divides by the usable coverage you enter, with an allowance for cuts and matching.
wall area × allowance ÷ usable roll coverage = rolls required
What to check before using the result
- Use the usable coverage recommended for the pattern and roll you are buying.
- Pattern repeat and drop matching can reduce the number of full-length drops obtainable from a roll.
- Subtract significant doors and windows, but keep enough allowance for trimming.
- Buying rolls from the same production batch can help avoid visible color variation.
A large repeat can force each strip to start at a matching point, creating offcuts at the top or bottom. That lost length reduces effective coverage, so usable roll coverage is more practical than raw roll area.