Wallpaper Calculator
Free wallpaper calculator. Estimate the number of rolls needed for any room based on wall dimensions, roll size, and pattern repeat — covers single-pattern jobs.
Quick answer
Rolls needed = (wall perimeter × wall height) ÷ roll coverage × pattern-match waste factor (1.10-1.25 depending on repeat). Standard double-roll bolts cover 56 sqft. Order at least 1 extra roll for repairs and dye-lot consistency.
Wallpaper Calculator
How it works
Calculates how many double rolls of wallpaper you need based on room perimeter, ceiling height, and the pattern repeat. Pattern repeat affects waste — a large repeat needs more material to match seams between strips.
When to use it
Use this before buying wallpaper for an accent wall or full room. Buy all the rolls from the same dye lot to avoid color variation between rolls, and add at least one extra roll as a buffer.
Common mistakes
Forgetting to account for the pattern repeat. A 24-inch repeat can waste 2 feet of material per strip. Also: not measuring around windows and doors — those areas reduce coverage but also reduce the number of strips you'll cut.
How the wallpaper calculator works
Total wall area = wall perimeter × ceiling height, minus doors and windows. Standard wallpaper rolls are sold as double-roll bolts covering 56 square feet. Pattern repeat adds waste — small repeats (3-6 inches) waste 5-10%, medium (12-18 inches) waste 10-15%, large (20+ inches) waste 15-25%. The calculator multiplies wall area by waste factor and divides by 56 to get rolls needed, rounded up.
When to use it
Estimating cost before ordering. Sizing the order so you don't run short mid-project. Comparing different patterns where pattern repeat affects total cost (small-repeat patterns can save 10-15% on a large room vs. big-repeat designs). Sanity-checking a wallpapering contractor's bid for a job.
Common mistakes
- Buying single rolls when bolts are double. Most wallpaper is sold as double-roll bolts. Coverage on the package may be listed per single roll (which doesn't exist as a SKU) — verify before ordering.
- Underestimating pattern-match waste. Drop-match patterns waste twice as much as straight-match. Read the pattern type on the roll label and add appropriate waste.
- Ordering to the calculator number with no margin. Order at least 1 extra bolt for repairs, mistakes, and future patches. Dye lots vary; a missing bolt 2 years later may not match.
Frequently asked questions
How many rolls of wallpaper do I need?
Calculate total wall area, multiply by pattern-repeat waste factor (1.10-1.25), and divide by roll coverage (typically 56 sqft for a double-roll bolt). The calculator does this automatically — enter room dimensions and roll specs.
Why does pattern repeat matter for wallpaper?
Each strip of wallpaper must align with the next at the pattern repeat. Larger repeats mean more wasted material at the top or bottom of each strip. Small repeats (under 6 inches) waste 5-10%; large repeats (18+ inches) can waste 25%.
Should I buy extra rolls?
Yes — at least 1 extra bolt. Future repairs (water damage, scuffs, picture hooks) need to match your existing dye lot. Dye lots change between manufacturer runs, so post-installation matches are often impossible without held-back stock.