Wallpaper Calculator

Enter your room dimensions and roll size. We'll size the order — pattern repeat eats more rolls than people expect.

Length (ft) Width (ft) Ceiling height (ft) Doors Windows

Roll type

Single roll (~28 sq ft) Double roll (~56 sq ft)

Advanced options

Pattern repeat (in) Roll width (in) Roll length (ft) — single Roll length (ft) — double Waste factor (%) Cost per roll ($)

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Wall area: 0 sq ft
With waste factor: 0 sq ft
Roll coverage: 0 sq ft usable
Strips needed: 0
Estimated cost: —

How the wallpaper calculator works

Two methods agree to within ~5% — we use the strip-based method for accuracy:

Wall area = perimeter × ceiling height − (doors × 20 sq ft / 1.86 m²) − (windows × 15 sq ft / 1.4 m²).
Strips needed = ceiling height (with pattern repeat added) ÷ roll length.
Number of strips = perimeter ÷ roll width.
Total rolls = strips per roll × strips needed.

Pattern repeat — the silent killer

Pattern repeat is the vertical distance after which the design starts over. A 19" repeat means every strip needs 19" added to align — and with an 8' ceiling, that's a 20% waste increase right there. Match that with a 15% standard waste factor and you're at 35% over your wall area. Always add the pattern repeat to your strip height before dividing.

Single roll vs double roll

Most modern wallpaper sells in double rolls (~33 ft / 10 m long) because that's enough for two ceiling-height strips, which reduces waste. Some imported and specialty papers still come in singles. Always check the roll specifications before ordering — particularly width (US 20.5" / 52 cm typical, but Euro often 53 cm).

Common questions

Why is wallpaper waste so much higher than paint waste?

Pattern matching forces you to align designs across strips, which means trimming the top of each strip to find the next pattern repeat. The bigger the repeat, the more you trim. A 12" repeat on an 8' ceiling needs a 9' strip cut from the roll, and the extra foot is mostly waste.

Should I buy from the same dye lot?

Always. Buy all your rolls from the same dye lot (printed on each roll) — even small batch differences are visible on a wall. Buy more than you need; if you run out at the end and the lot is gone, you'll be patching with visibly different paper.

Pre-pasted vs traditional?

Pre-pasted is far easier for DIY — wet the back, let it activate, hang. Traditional needs separate wallpaper paste applied to each strip; better for thick papers and commercial work. Most modern residential wallpaper is pre-pasted.