Calculate wallpaper rolls from wall area, doors, windows and pattern repeat before you buy.
Quick answer: Wallpaper is sold in single and double rolls, and a US double roll typically covers about 56 sq ft. A 10 by 12 ft room with 8 ft ceilings has 352 sq ft of wall; taking off about 40 sq ft for a door and two windows leaves 312 sq ft, which is roughly 6 double rolls before allowing for pattern repeat.
How do you want to enter the area?
sq ft
%
Straight match 5–10%, half-drop 15%, large repeat 20%+.
$
Wallpaper ranges enormously — $25 to $150+ per roll depending on designer and material.
Smoothing tool & seam rollerone of each; a sharp blade per 6–8 strips
Ordering one extra roll beats a mid-job shortage: dye lots, tile calibre and wallpaper print runs change between batches, so a later top-up may not match what you already installed.
Every coverage figure here is typical, not exact: box sizes, sheet sizes, roll widths and bag yields change between brands. Check the label on the product you actually buy and round up — a second trip costs more than a spare box.
Core facts
US double roll
about 56 sq ft, typical
US single roll
about 28 sq ft, typical
Pattern repeat waste
10–25% depending on repeat size
Sold as
usually double rolls in the US
What is Wallpaper Calculator?
Wallpaper estimating looks like a simple area calculation until the pattern arrives. The wall area is straightforward: perimeter times ceiling height, less large openings. But wallpaper hangs in vertical strips that must match at the seams, and any pattern with a repeat forces you to cut each strip longer than the wall height so the design lines up. A large repeat can waste a quarter of every roll. Rolls are also sold in confusing sizes. A US double roll covers roughly 56 square feet, while a European roll is usually longer and narrower. Read the label before trusting any general figure.
Common uses for Wallpaper Calculator
Work out rolls for a bedroom before ordering wallpaper
Allow for pattern repeat on a large floral or geometric design
Subtract doors and windows from a wall area estimate
Compare single and double roll prices on the same pattern
Plan a single feature wall without overbuying rolls
Wall area is the easy part
Measure the room's perimeter, multiply by ceiling height, and subtract large openings. That gives gross wall area in square feet. Doors, windows and built-in cabinets that will not be papered come off the total, though small openings are usually left in as a safety margin. This number is the starting point rather than the answer, because pattern matching changes it.
Pattern repeat is the hidden cost
Every strip must align with its neighbor, so a pattern with a large repeat forces you to start each strip at a matching point and cut off the excess. With a 24 inch repeat on 8 ft walls, a strip may need nearly 10 ft of paper. Random-match and free-match patterns waste far less. Check the repeat before comparing prices between two patterns.
Buying, hanging and spares
Buy all the rolls you need in one purchase, because different production runs of the same pattern can vary slightly in color and the difference shows at a seam. Keep one spare roll for future repairs. Hanging is easier than most people expect: paste the wall or the paper as directed, book the strips to let them relax, then trim at the ceiling and baseboard.
Frequently Asked Questions
How many square feet does a roll of wallpaper cover?
In the US a double roll typically covers about 56 sq ft and a single roll about 28 sq ft, though many patterns are sold only in double rolls. European rolls are usually longer and narrower and cover a similar area. The label states the coverage for that specific product, so use it rather than a rule of thumb.
How much extra should I allow for pattern repeat?
Add roughly 10 percent for a small repeat of a few inches, 15 percent for a medium repeat, and 20 to 25 percent for large repeats that force you to discard most of a strip. Straight-match patterns waste more than random or free matches. The pattern's specification sheet usually quotes the repeat in inches.
Should I subtract doors and windows?
Subtract large openings such as patio doors and big windows, but do not bother with small ones. Offcuts above and below a window are usable on the same wall, and being generous here protects you from a shortfall. A typical deduction for a normal room lands somewhere around 20 to 40 sq ft.
What is the difference between a single and double roll?
A double roll is two single rolls wound together, and it is how most wallpaper is sold in the US. It is not always exactly twice the length of a standard roll, because the naming is inconsistent between manufacturers. Compare products on the coverage stated on the label rather than on the word on the wrapper.
Can I wallpaper over existing wallpaper?
Sometimes, if the old paper is firmly adhered, has no bubbles and the surface is smooth, but it is risky. Moisture from new paste can loosen the old layer, and any texture underneath shows through. Removing the old paper and sizing the wall gives a much better result and costs only a weekend of work.