How many rolls of wallpaper do I need?

Common questions

How many rolls of wallpaper do I need?

Measure the room's perimeter (twice the length plus twice the width) and the wall height. Wallpaper hangs in full-height vertical strips called drops, so work out how many drops you can cut from one roll — roll length divided by wall height, rounded down — and how many drops you need to go round the room — perimeter divided by the roll width, rounded up. Divide the drops needed by the drops per roll and round up. A 12 ft × 12 ft room with 8 ft walls needs about 8 standard rolls; a 3.6 × 3.6 m room with 2.4 m walls needs about 7. The calculator above does it for you.

How many rolls of wallpaper for a 12x12 room?

A 12 × 12 ft room has a 48 ft perimeter. With 8 ft walls and a standard double roll (about 33 ft long and 20.5 in wide) you can cut 4 full drops per roll, and the room needs 29 drops to go round, so that is about 8 rolls. Add a roll if your paper has a large pattern repeat, because matching the pattern wastes part of every strip.

Why count drops instead of just area?

Because wallpaper is cut into full-height strips, the leftover at the end of a roll that is shorter than one wall height cannot be used and becomes waste. A flat area calculation ignores that offcut and almost always under-orders. Counting whole drops — how many full strips a roll yields, and how many strips the room needs — captures the real waste, which is why this calculator uses it.

What is a pattern repeat and how does it change the count?

The pattern repeat is the vertical distance before the design starts again. To line the pattern up with the next strip you slide the paper up or down, which wastes up to one repeat on every drop. A plain paper has a repeat of zero and wastes the least. Enter the repeat (printed on the roll label) in the calculator and it adds it to each drop, which can drop the number of usable strips per roll and push you up a roll or two.

How much extra wallpaper should I buy for waste?

The drop method already builds in the main source of waste — the unusable offcut at the end of each roll — so for a plain paper you often need no extra. For a large pattern repeat, an irregular room, or your first time hanging paper, add roughly 10–15% with the extra-waste field, and always buy every roll in a single order so the batch (shade) number matches, since dye lots vary slightly between print runs.

Do you subtract doors and windows when measuring for wallpaper?

For normal doors and windows, no — leave them in. The strips above and below an opening are usually too short to reuse elsewhere, so they become your spare, and deducting them tends to leave you short. Only subtract genuinely large openings, such as a full wall of patio doors or a wide picture window, and even then round generously.

Want the full walk-through? Read the wallpaper guide →