Wallpaper Calculator
The Wallpaper Calculator estimates how many rolls you need based on your wall size and standard roll dimensions, with an adjustable waste allowance for pattern matching. Works in U.S. or metric units. The formula treats roll coverage as pure area (roll width × roll length) and divides your total wall area into that pool, but real installations buy rolls by usable full-height strip count, not raw square footage — a 9 ft wall on a 33 ft roll yields only 3 full-height strips with a wasted stub left over, which can mean needing more rolls than the area math alone suggests. Because the waste factor is applied uniformly across the whole area rather than per roll, it's a rough stand-in for pattern-matching loss rather than an exact model — large repeat patterns of 18 inches or more often eat closer to 25–30% versus the 15% default, so increase it for bold or oversized prints. Roll dimensions vary by brand and region (U.S. rolls commonly run 20.5 or 27 inches wide; European rolls are usually 52 cm × 10 m), so always confirm the dimensions printed on your specific roll rather than relying on the defaults.
Switch between U.S. Customary and Metric units.
How This Tool Works
Pick your units, then enter your total wall length and height, along with your wallpaper roll's dimensions, to calculate how many rolls to order.
Formula & Method
Roll coverage = roll width × roll length. Rolls needed = (wall area × (1 + waste%)) ÷ roll coverage. Enter walls in feet with roll width in inches, or in meters with roll width in centimeters.
Example Calculation
A 30 ft long, 9 ft high wall (270 sq ft) using the default 20.5 in × 33 ft rolls (56.375 sq ft each) with 15% waste: area with waste = 270 × 1.15 = 310.5 sq ft. Rolls needed = ceil(310.5 ÷ 56.375) = ceil(5.51) = 6 rolls. In metric, a 9×2.7 m wall (24.3 m²) using the default 52 cm × 10 m rolls (about 5.2 m² each) with 15% waste needs area with waste = 24.3 × 1.15 = 27.945 m², divided by 5.2 m² per roll ≈ 5.37, also rounded up to 6 rolls.
Frequently Asked Questions
Why is the waste factor higher for wallpaper than paint?+
Wallpaper often has a repeating pattern that must line up between strips, which wastes more material than a solid paint color — 15% is a safe default, more for large repeats.
Can I calculate wallpaper in meters?+
Yes — switch the unit toggle to Metric and enter your wall in meters with the roll width in centimeters and roll length in meters (typical European rolls are 52 cm × 10 m).
Should I subtract doors and windows?+
For a rough estimate you can skip small deductions, since offcuts from door and window areas often get reused above or below openings. For precision, measure each wall segment individually.
What if my rolls are a different size?+
Just update the roll width and length fields — the calculator will recompute the coverage per roll automatically.
Does this account for how many strips fit per roll?+
No — it works purely from total area, not from how many full-height strips a roll actually yields. Leftover stubs at the end of a roll usually can't be reused on the next wall, so tall walls or an awkward roll-length remainder often need one more roll than the area math alone implies — round up your final total by one when in doubt.
My wallpaper has a large pattern repeat — should I change anything besides the waste factor?+
Increase the waste factor field — 15% covers small or no-repeat patterns, but repeats of 18 inches or more can waste 25–30% of each roll to alignment, and very large repeats (24+ inches) sometimes need even more. Check your wallpaper's spec sheet for the printed repeat measurement before finalizing your order.
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<a href="https://everyfix.net/tools/wallpaper-calculator/">Wallpaper Calculator</a> by <a href="https://everyfix.net">EveryFix</a>Related Tools
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