Physical rolls, not marketing labels
Enter the dimensions of one physical roll. The optional pack field says how many physical rolls are actually included in a sale unit; do not guess from “single” or “double” alone.
A strip-based method
For one wall, divide its width by the roll width and round up to full strips. Add your trim to the wall height. Straight-match cuts round up to a whole pattern repeat, and this conservative model reserves one repeat at the start of each roll.
Important exclusions
We do not subtract doors or windows, reuse offcuts or pool strips around corners. Half-drop, offset matches, murals and precut panel systems need a product-specific plan and are not supported.
For example, a 120-inch wall with 20.5-inch-wide paper requires six full-width strips. With 100-inch cuts and a 396-inch physical roll, three strips fit per roll, requiring two rolls.
Manufacturer context: one wallpaper maker describes a single roll as typically 21 in × 16.5 ft and a double roll as 21 in × 33 ft, adds that “there can be variations in these measurements depending on the manufacturer”, and sells its own paper as 24 in × 33 ft (Milton & King, single vs double roll). The same maker’s measuring guide says not to subtract windows and doors and excludes murals and panel designs (Milton & King, how many rolls) — the same boundaries this calculator keeps. The roll-start reserve for straight match is this project’s stated modeling choice, not a universal manufacturer rule.
Not sure what to measure? Read how to measure a room for paint, wallpaper and flooring.