Why does the calculator not subtract doors and windows?

Wallpaper is ordered as full-height strips, and openings rarely eliminate a predictable number of strips. Keeping them included usually provides a safer planning estimate.

What is pattern repeat?

It is the vertical distance before the design repeats. Strip length is rounded up to a full repeat so neighboring pieces can align.

What if the wallpaper has a drop match?

Drop-match alignment can consume more material than a simple vertical-repeat calculation. Check the manufacturer's match instructions or ask the installer before ordering.

Should I order an extra roll?

An extra roll from the same batch can help with installation mistakes and future repairs, especially when a design may be discontinued. Whether it is necessary depends on the product and project.

Home project calculator

Wallpaper Calculator

Estimate wallpaper rolls using full-height strips, actual roll dimensions, trim allowance and vertical pattern repeat.

Live estimate

Enter project measurements

Total wall lengthftWall heightftRoll widthinRoll lengthftVertical repeatinTrim per stripin

Estimated wallpaper

8 rolls

Based on full-height strips and the entered vertical repeat.

Gross wall area: 320 ft²
Strips needed: 24
Strip length: 9 ft
Strips per roll: 3

Transparent calculation

Formula used

Rolls = required strips ÷ full-height strips per roll

Each strip is rounded up to the next full vertical pattern repeat after trim allowance. This strip method is more useful than dividing wall area by nominal roll area.

Worked example

For 40 linear ft of 8 ft walls, 20.5 inch-wide paper needs 24 strips. A 33 ft roll yields three 9 ft pattern-adjusted strips, so the estimate is eight rolls.

How to use this estimate

1Add the linear length of all walls receiving wallpaper.
2Enter wall height and the exact roll width and length.
3Copy the vertical pattern repeat from the product specification.
4Confirm match type, openings and batch availability before ordering.

Wallpaper Calculator FAQs

Answers to the most common measurement and ordering questions.