Wallpaper Calculator

Estimate wallpaper rolls using proper strip math — including your pattern repeat.

On the label — U.S. rolls are usually 20.5″ or 27″.
U.S. double rolls are usually 33 ft.
0 for solid/random patterns. On the label for others.

Your info stays on your device. We don’t store anything.

How to measure for wallpaper

Measure the room’s perimeter (all walls you’re papering) and the wall height floor to ceiling. The roll width, length, and pattern repeat are printed on the label.

How we calculated it

Wallpaper hangs in vertical strips, so we count strips instead of raw square footage: the room’s perimeter divided by the roll width. Each strip needs your wall height plus trim — rounded up to a full pattern repeat if your paper has one. Rolls ÷ strips-per-roll gives the buy count.

Things that can change your result
  • Pattern repeat is the big variable — a 24″ repeat can turn a 3-strip roll into a 2-strip roll.
  • We don’t subtract doors and windows: their offcuts are rarely reusable and the margin covers mistakes.
  • US rolls are commonly sold as double rolls (about 33 ft) — check what the price is quoting.
Buying tips
  • Buy all rolls from the same batch number; wallpaper dyes shift between runs.
  • One spare roll is standard practice for a first-time hang.
  • Random-match and solid papers waste far less — a repeat of 0 in the calculator.
Common mistakes
  • Ignoring the pattern repeat and coming up a roll short.
  • Mixing batch numbers.
  • Measuring a single wall’s width when papering the whole room.
Frequently asked questions

How many rolls of wallpaper for a 12×10 room?

With 8-foot walls and standard 20.5″ × 33 ft double rolls, about 26 strips at 3 strips per roll — 9 rolls with no pattern repeat.

What does pattern repeat mean?

The vertical distance before the design repeats. Every strip must start at the same point in the pattern, so each strip gets rounded up to a whole repeat — that’s the waste.

Should I subtract windows and doors?

For estimating, no — the cut pieces are rarely usable elsewhere, and the small overage covers trimming errors.