Wallpaper Calculator
Calculate how many rolls of wallpaper are needed for a room based on wall perimeter, height, and door/window cutouts.
ft
ft
ft
sq ft
sq ft
Common single rolls cover ~30 sq ft usable after pattern-matching waste
Results
Rolls Needed
14
Wall Perimeter
52.0 ft
Gross Wall Area
416 sq ft
Net Wallpaper Area
396 sq ft
How the Wallpaper Calculator Works
Enter your room's length and width to get the wall perimeter, then the wall height to get the total wall area. Subtract the combined area of doors and windows you won't be papering over, then divide the remaining net area by the usable coverage of a single roll (accounting for pattern-matching waste) to get the number of rolls needed for the whole room.
This tool calculates the full room job — perimeter, gross area, net area, and roll count together. If you already know your total area and just want to check how far a single roll goes on its own, see our separate Wallpaper Roll Calculator for that narrower reference calculation.
Example
A 14 ft × 12 ft room with 8 ft walls has a perimeter of 2 × (14 + 12) = 52 ft, giving a gross wall area of 52 × 8 = 416 sq ft. Subtracting 20 sq ft for doors and windows leaves 396 sq ft. At 30 sq ft of usable coverage per roll, that's 396 ÷ 30 = 13.2, rounded up to 14 rolls.
Common Use Cases
- Estimating how many rolls to buy before a wallpapering project.
- Budgeting material costs for a room renovation.
- Comparing material needs between different rooms before choosing a wallpaper pattern.
- Avoiding running short mid-project by buying with a reasonable waste margin.
FAQs
Why is usable coverage less than the roll's full size?
Most wallpaper rolls have a nominal size larger than what you can actually use, since pattern matching between strips, trimming at ceiling and floor lines, and waste from mistakes all reduce the effective coverage. A common rule of thumb is around 30 sq ft of usable coverage per single roll, though busier repeat patterns waste more.
Should I round up or buy extra rolls?
Yes — this calculator already rounds up to the next whole roll, but many installers recommend buying one extra roll beyond that for touch-ups, mistakes, or future repairs, especially for patterns that may be discontinued later.
Does this account for the wallpaper pattern repeat?
Not directly — pattern repeat waste is folded into the "usable coverage per roll" figure you enter. Wallpapers with a large pattern repeat need a lower usable-coverage estimate than plain or small-repeat patterns; check the manufacturer's own coverage guidance for your specific wallpaper.