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Wallpaper Calculator
Calculate single rolls, double rolls, and material cost for any wallpaper project
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Wallpaper Calculator
How to Calculate Wallpaper
Wallpaper calculation is more complex than paint because roll sizes vary by manufacturer and pattern matching adds significant waste. Always measure the actual roll dimensions before calculating.
Wallpaper Formula
Wall Area = (2L + 2W) × H − Doors×21 − Windows×15
Roll Coverage = (Roll Length × Roll Width) ÷ 144
Rolls Needed = ⌈(Wall Area ÷ Roll Coverage) × 1.15⌉
Wall Area = (2L + 2W) × H − Doors×21 − Windows×15
Roll Coverage = (Roll Length × Roll Width) ÷ 144
Rolls Needed = ⌈(Wall Area ÷ Roll Coverage) × 1.15⌉
Standard Roll Size Reference
| Roll Type | Width | Length | Coverage |
|---|---|---|---|
| US Single Roll | 21" | 27 ft | ~36 sq ft |
| European Single | 20.5" | 33 ft | ~45 sq ft |
| Wide Wallpaper | 27" | 27 ft | ~45 sq ft |
| Commercial | 54" | 30 ft | ~135 sq ft |
Wallpaper Installation Tips
- Order all rolls from the same batch (run/dye lot) to ensure color consistency
- Prepare walls: fill holes, sand smooth, and apply sizing or primer
- Start in a corner that's not highly visible (like behind a door)
- Use a plumb line to ensure the first strip is perfectly vertical
- Match patterns at eye level (4–5 ft from floor) for the best visual result
? Frequently Asked Questions
How many rolls of wallpaper do I need?
Calculate your total wall area (perimeter × height), subtract openings for doors (21 sq ft each) and windows (15 sq ft each), then divide by the roll coverage. Add 15% for pattern matching waste. Our calculator does this for any roll size.
What is a standard wallpaper roll size?
US single rolls: 21" wide × 27 ft long = 4.75 sq ft. European single rolls: 20.5" wide × 33 ft long = 5.6 sq ft. Wallpaper is often sold in double rolls (2× the length). Always verify with your specific product.
What is a double roll of wallpaper?
A double roll contains twice as much wallpaper as a single roll but is priced as one unit. This reduces the number of seams and is actually more economical. When contractors quote 'rolls needed,' they typically mean single rolls.
How much does wallpaper installation cost?
Professional wallpaper installation costs $1–$7 per sq ft for labor, depending on pattern complexity and wall condition. Simple wallpaper runs $1–$3/sq ft to install. Budget wallpaper materials: $25–$50/single roll. Premium: $75–$150+/roll.
How do I measure walls for wallpaper?
Measure each wall's width and height. Calculate total square footage, then subtract openings. For rooms with many windows and doors, you may only need 60–70% of the gross wall area covered. Always use actual measurements, not estimated room size.
Related Calculators
💡 Pro Tips
Always add 10% extra to material estimates to account for waste, cuts, and mistakes.