Wallpaper Calculator

About this calculator

This calculator estimates how many rolls of wallpaper are needed for a room by dividing the total wall area by the usable coverage per roll (typically around 5 m² after allowing for pattern matching and trim waste), then rounding up since partial rolls can't be bought. Pattern repeat, roll width, and waste allowance all affect the real number needed, which is why installers typically buy slightly more than the raw area calculation suggests.

DIY homeowners and professional decorators use it before a shopping trip to avoid running short mid-job or over-ordering, especially important since wallpaper dye lots can vary between batches. Enter the wall dimensions and the coverage per roll to get the number of rolls needed.