Wallpaper Calculator

This wallpaper calculator estimates the number of rolls needed to wallpaper a rectangular room. Enter the room dimensions, ceiling height, number of doors and windows to subtract, and the coverage of your specific wallpaper roll. Standard US wallpaper rolls cover approximately 56 square feet, but this varies — European single rolls cover about 29 sq ft and double rolls cover about 57 sq ft. Always check the square footage listed on your wallpaper label. The calculator subtracts door area (21 sq ft) and window area (15 sq ft) for each opening and rounds up to whole rolls, then adds one extra roll as a buffer for pattern matching, waste, and future repairs. Patterned wallpaper with a large repeat requires significantly more material — add 10–20% extra depending on the pattern repeat size.

Total wall area = 2 × (length + width) × height — the combined area of all four walls. Deductions: each door reduces the area by 21 sq ft (a standard 3×7 ft door); each window by 15 sq ft (an average double-hung window). Coverable area = total wall area − deductions. Rolls needed = ceil(coverable area ÷ roll coverage). One additional roll is added as a buffer for pattern matching waste, trimming errors, and future touch-up repairs. Always buy from the same production run (same batch number) to ensure color and pattern consistency — wallpaper can vary subtly between batches. For rooms with large pattern repeats (12 inches or more), consider adding an additional 10–20% to the coverable area before dividing by roll coverage, as more material is wasted aligning the pattern at each seam.