Wallpaper Calculator
Calculate wallpaper rolls needed with pattern repeat, waste factor, and cost estimation
Room Measurements
Enter your wall dimensions
Area: 96.0 sq ft
3' × 7' each
3' × 5' each
0 for no pattern or random match
Typical: 10-15% standard, 15-20% complex patterns
Area Calculations
Materials & Cost
Rolls Needed
0
Including 10% waste factor
Note: Consider ordering 1-2 extra rolls for future repairs or pattern matching errors. Dye lots can vary between production runs.
Area Breakdown
Cost Breakdown
Common Wallpaper Roll Sizes
US Single Roll
20.5" × 16.5'
~28 sq ft coverage
US Double Roll
20.5" × 33'
~56 sq ft coverage
European Roll
27" × 33'
~75 sq ft coverage
Frequently Asked Questions
How do I measure walls for wallpaper?
Measure the length and height of each wall in feet. Measure from corner to corner for length, and floor to ceiling for height. Don't subtract doors and windows during measurement - the calculator will account for those separately.
What is pattern repeat and why does it matter?
Pattern repeat is the vertical distance before the wallpaper pattern repeats. When hanging wallpaper, you need to match patterns between strips, which creates waste. A 24-inch repeat means you may waste up to 24 inches per strip to align patterns.
How much waste factor should I add?
Standard waste factor is 10-15% for straight patterns and 15-20% for drop match or large patterns. This accounts for cutting waste, mistakes, and pattern matching. Complex patterns or tricky room layouts may need 20-25%.
What is the standard wallpaper roll size?
In the US, standard single rolls are typically 20.5 inches wide and 16.5 feet long (about 28 sq ft). However, most wallpaper is sold in double or triple rolls. European rolls are often wider (21 inches or 27 inches) and longer (33 feet or more).
Should I subtract doors and windows?
Yes, but conservatively. This calculator uses standard sizes: doors (3' × 7' = 21 sq ft) and windows (3' × 5' = 15 sq ft). For small windows or complex layouts, you may want to reduce the count to avoid ordering too little.
How many square feet does one roll cover?
A standard US single roll (20.5" × 16.5') covers about 28 sq ft, but usable coverage is typically 25 sq ft after waste. Double rolls cover about 50 usable sq ft. Pattern repeats reduce usable coverage, sometimes significantly for large repeats.
Can I wallpaper over existing wallpaper?
It's possible but not recommended. New wallpaper adheres best to smooth, clean walls. Old wallpaper may bubble, peel, or show through. If the existing wallpaper is in perfect condition and firmly attached, you might succeed, but removing old wallpaper is usually better.
What tools do I need to hang wallpaper?
Essential tools: tape measure, level, sharp utility knife, wallpaper brush or smoother, bucket/tray, sponge, seam roller, and scissors. For paste-the-wall paper, you'll need a paint roller and tray. For traditional paper, add a pasting table.
How do I calculate for sloped or cathedral ceilings?
For sloped walls, measure as triangles. Measure the base (width) and height (from base to peak). Area = (base × height) / 2. Add these triangular areas to your rectangular wall measurements. Consider adding extra waste factor (15-20%) for angled cuts.
How much does wallpaper installation cost?
Professional installation typically costs $3-7 per square foot, depending on pattern complexity, wall condition, and location. A 12' × 12' room (about 400 sq ft of wall) would cost $1,200-2,800 for labor alone, plus materials.
What Users Say
"This calculator is incredibly accurate! The pattern repeat feature is essential for avoiding costly mistakes. I use it for every wallpaper project to give clients precise estimates."
Sarah Mitchell
Interior Designer
"Saves me so much time on wallpaper estimates. The waste factor calculations are spot-on, and my clients appreciate the detailed breakdowns. Highly recommend!"
Tom Bradley
Painting Contractor
"Wallpapered my dining room using this calculator and ordered exactly the right amount! The pattern repeat explanation helped me understand why I needed extra rolls."
Lisa Chen
DIY Homeowner
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