Picking Your Roll Width
One of the most important things to consider when estimating how many rolls of wallpaper you'll need is width. Many wallpaper hangers will simply refer to the rolls as American or English. American wallpaper tends to be 27 inches in width, while English wallpaper is more commonly found measuring 20.5 inches. The best way to estimate the amount of rolls needed is to consult with a professional paper hanger.