Total wall length to paper (ft), wall height (ft), roll width (in), roll length (ft)—strips and rolls (rounded up).
Wall perimeter (or run length) and wall height are in feet; roll width is in inches (converted to feet for strip width). Strips = ⌈length ÷ strip_width⌉. Strips per roll = ⌊roll_length ÷ wall_height⌋ (must be ≥1). Rolls = ⌈strips ÷ strips_per_roll⌉. Pattern repeat and waste are not modeled.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.