Wallpaper Calculator
Wallpaper calculator finds the number of wallpaper rolls you need to buy for your room.
Rolls needed823 drops at 3 per roll
Drops required2440 ft of wall at 20.5 in per drop
Drops saved by openings11 door and 2 windows
Cut length per drop9 ftno pattern to match
Drops per roll333 ft roll ÷ 9 ft drop
Wall area360 sq ft
Paper bought451 sq ft
Waste97.37 sq ft21.6% of what you buy
Buy an extra roll9 to be safedye lots differ, so a later roll may not match
The formula
rolls = wall area ÷ usable coverage per roll, allowing for pattern repeat
The pattern repeat is the hidden cost
Wallpaper is hung in full-height drops, and with a patterned paper every drop must start at the same point in the pattern. So a 9-foot wall with an 18-inch repeat needs each drop cut to 10 feet 6 inches — six whole repeats — and the offcut is usually unusable.
That is why a large repeat can add a fifth to the order, and why plain papers go so much further. Work in drops rather than area: it is the only way to account for it.
Order all of it at once from the same batch. Wallpaper dye lots vary just enough to be visible on a long wall.