Wallpaper Square Footage Calculator

Most wallpaper is sold in "double rolls" — a single bolt that contains two rolls' worth. A standard double roll covers 56 sq ft after typical pattern matching.

Some imported papers come in single rolls (28 sq ft). Always check the label, because the math is very different.

Wallpaper patterns repeat at fixed intervals. A 19-inch pattern repeat means every strip starts at a 19-inch increment, so you waste material aligning patterns. The bigger the repeat, the more waste.

Add 15% for standard repeats (under 18 inches). Add 20% for large repeats (over 18 inches). Add 25% for very large or random match patterns.

Wallpaper coverage is one of the most confusing topics because rolls come in two completely different size standards, and the rated coverage is rarely the practical coverage.

American (single) rolls: 27 inches wide × about 15.5 ft long = 33-35 sq ft per roll. Practical coverage after pattern matching: 27 sq ft.

European (double) rolls: 21 inches wide × 33 ft long = 56-57 sq ft per roll. Practical coverage: 50 sq ft.

British rolls: 21 inches wide × 33 ft long = 56 sq ft (same as European double).

Always confirm which type you're buying — many US retailers sell European rolls labeled simply 'roll,' which makes pricing look 2× higher than it actually is per usable foot.

Wallpaper pattern repeat is the vertical distance between identical pattern elements. Larger repeats waste more material because each new strip has to be cut to align with the previous strip's pattern.

Solid colors or no-match patterns: 0% pattern waste. Practical coverage = rated coverage.

Random match patterns (no specific alignment needed): 5-10% pattern waste.

Small repeat (under 6 inches): 10-15% pattern waste. Common for traditional patterns.

Medium repeat (6-18 inches): 15-20% pattern waste. Most popular patterns fall here.

Large repeat (over 18 inches): 25-30% pattern waste. Big florals, scenic patterns, large geometric prints.

Drop match patterns (pattern offsets every other strip): add 5% to the above. Common in toile and damask.

Here's the full math for a typical bedroom wallpapering project: 12 × 14 ft room with 8 ft ceilings, 1 door, 2 windows, medium-repeat pattern.

Step 1 — gross wall area: perimeter (52 ft) × ceiling (8 ft) = 416 sq ft.

Step 2 — subtract openings: 1 standard door (17.8 sq ft) + 2 windows (15 sq ft each) = 47.8 sq ft. Net wall area = 368.2 sq ft.

Step 3 — apply pattern waste: 368.2 × 1.18 (18% medium-repeat waste) = 434.5 sq ft of paper needed.

Step 4 — divide by practical roll coverage. US single rolls (27 sq ft practical): 434.5 ÷ 27 = 16.1 rolls → order 17. European/UK rolls (50 sq ft practical): 434.5 ÷ 50 = 8.7 rolls → order 9.

Always order from the same dye lot. Reorders weeks later are gambling — manufacturers can't guarantee identical color across runs.