How many wallpaper rolls do I need?

What the Wallpaper Calculator Does

This wallpaper calculator estimates how many rolls of wallpaper you need to cover a wall or room. You enter the wall area you want to paper and the coverage of a single roll, and the tool returns the number of full rolls required.

It is built for DIY decorators, renovators, and anyone buying wallpaper online or in store. Knowing your wallpaper rolls upfront prevents two common headaches: running short mid-job (and risking a different dye lot on the reorder) or overbuying and wasting money on rolls you cannot return once opened.

How It Works: The Wallpaper Rolls Formula

The calculation is deliberately simple. You divide the total wall area by the area one roll covers, then round up to the next whole roll because shops sell rolls whole, not in fractions.

rolls = ceil(wallArea / rollCoverage)

Wall area and roll coverage must use the same unit (both in square metres, or both in square feet). A standard European roll is about 10.05 m long and 0.53 m wide, giving roughly 5.3 m² of paper. Roll coverage on the label is usually less than that raw figure once trimming and pattern matching are accounted for, so always use the coverage value the manufacturer prints, not the raw roll dimensions.

Worked Example With Real Numbers

Imagine a room measuring 4 m by 3 m with a 2.4 m ceiling height. Add the four wall lengths: 4 + 3 + 4 + 3 = 14 m of perimeter. Multiply by height: 14 x 2.4 = 33.6 m² of wall area.

Suppose each roll covers 5 m² after trimming. Then rolls = ceil(33.6 / 5) = ceil(6.72) = 7 rolls.

If you subtract a standard door (about 1.8 m²) and one window (about 1.5 m²), the area drops to roughly 30.3 m². rolls = ceil(30.3 / 5) = ceil(6.06) = 7 rolls. Notice it still rounds up to 7 — that small margin is your safety buffer for mistakes and offcuts.

Pattern Repeat: The Factor People Forget

The single biggest variable the basic formula does not capture is the pattern repeat. Patterned wallpaper must be aligned strip to strip, so part of every drop is cut off and discarded as waste. The larger the repeat, the more you lose.

Use these rough guides when choosing your roll coverage figure or adding rolls:

• Plain or random match (no repeat): little waste, use coverage as printed.
• Small repeat (under 15 cm): add roughly 10 percent extra.
• Large or drop-match repeat (over 30 cm): add roughly 15 to 25 percent extra.
• Tall ceilings or stairwells with long drops: waste rises, so round generously.

Tips and Common Mistakes

A few habits keep your estimate reliable and your finish clean.

Measure carefully and double-check before you buy, because reorders may not match.

• Buy all rolls in one purchase and check that the batch (dye lot) number matches on every roll.
• Do not deduct small features like a single window unless the calculator already accounts for them — that extra paper covers mismatched cuts.
• Buy at least one spare roll for future repairs of scuffs or damage; matching the lot later is often impossible.
• Confirm whether your roll coverage is metric or imperial, and never mix the two in the same calculation.
• For feature walls, measure only that wall, not the full room perimeter.