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Wallpaper Calculator – Calculate How Many Rolls You Need for Your Room

Avoid over- or under-buying wallpaper with our free Wallpaper Calculator. Enter your room dimensions and roll size to instantly find out how many rolls you need, including a waste allowance for pattern matching.

Doors & Windows

Wallpaper Roll Specs

Check wallpaper label for pattern repeat measurement

Wallpaper Estimate Results

Enter values and click Calculate to see results

How to Calculate Wallpaper Needed

Wall Area = Perimeter × Height
Net Area = Wall Area - (Doors + Windows)
Roll Area = Roll Length × Roll Width
Rolls Needed = (Net Area ÷ Roll Area) × (1 + Waste Factor)

Standard US roll: 33 ft × 20.5 in = 56 sq ft
Standard EU roll: 10 m × 53 cm = 57 sq ft
Waste factor: 10% for no pattern, 15-25% for pattern matching

How to Calculate Wallpaper Needed

1

Measure Your Room

Input room length, width, and ceiling height. Measure in feet or meters.

2

Add Openings

Enter door and window dimensions to subtract areas that won't be papered.

3

Get Roll Count

Enter roll specs and pattern repeat to get exact number of rolls needed.

Key Features of This Wallpaper Calculator

**Pattern Repeat Support**

Accounts for extra wallpaper needed when matching patterns across strips.

**Door & Window Deduction**

Automatically subtracts areas that won't be covered to avoid overbuying.

**Waste Factor Calculation**

Includes recommended waste percentage for trimming and mistakes.

**Dual Unit Support**

Works with both imperial (feet) and metric (meters) measurements.

Frequently Asked Questions

How do I measure my room for wallpaper?

Measure the perimeter (add length + width, multiply by 2) and multiply by ceiling height. This gives total wall area before subtracting doors and windows.

What is pattern repeat?

Pattern repeat is the vertical distance before the design repeats. Larger repeats require more wallpaper because you need to align the pattern between strips.

How much extra wallpaper should I buy?

Add 10-15% for simple patterns, 15-25% for large pattern repeats. Always buy an extra roll for future repairs if possible.

What size is a standard wallpaper roll?

US standard: 33 ft long × 20.5 in wide (56 sq ft). European standard: 10 m long × 53 cm wide (57 sq ft). Always check your specific roll dimensions.

Should I remove doors and windows from calculation?

Yes, but professionals often don't subtract small windows. For DIY, subtract all openings but add extra for waste to be safe.