Pine Tools Hub

Wallpaper Calculator

Calculate exactly how many rolls of wallpaper you need, factoring in pattern repeats, doors, and windows.

Room Dimensions

Wallpaper Details

$

Wallpaper Required

Rolls to Buy0
Total Wall Area0 sq ft
Exact Rolls (No Waste)0 rolls

If your wallpaper has a large pattern repeat, you may need additional rolls to align the design correctly.

How This Calculator Works

Estimating wallpaper correctly is critical to avoid running out mid-project, especially since different batches (dye lots) of the same wallpaper can have slight color variations. Our calculator uses industry-standard math to determine your exact needs.

The Formula

1. Gross Wall Area: (Room Length × 2) + (Room Width × 2) × Ceiling Height
2. Net Wall Area: Gross Wall Area - (Doors × 21 sq ft) - (Windows × 12 sq ft)
3. Usable Roll Area: Roll Width × Roll Length (minus pattern repeat waste)
4. Rolls Required: (Net Wall Area / Usable Roll Area) + 10% Waste

Worked Example

Suppose you have a 12 ft by 10 ft room with an 8 ft ceiling, 1 door, and 2 windows.

Wall Perimeter: (12 + 10) × 2 = 44 ft
Gross Area: 44 ft × 8 ft = 352 sq ft
Deductions: (1 × 21) + (2 × 12) = 45 sq ft
Net Area: 352 - 45 = 307 sq ft

If your wallpaper roll covers 28 sq ft: 307 / 28 = 10.96 rolls.
Adding 10% waste means you should purchase 13 rolls to be safe.

Frequently Asked Questions

How do I calculate how much wallpaper I need?
To calculate how much wallpaper you need, multiply the total width of your walls by your ceiling height to get the gross wall area. Subtract the area of any doors (typically 21 sq ft) and windows (typically 12 sq ft). Finally, divide the net wall area by the usable square footage of your wallpaper roll.
What is a pattern repeat and why does it matter?
A pattern repeat is the vertical distance between where the wallpaper pattern perfectly duplicates itself. It matters because matching the pattern across strips requires you to trim and discard excess paper. A larger pattern repeat requires ordering more wallpaper to account for this increased waste.
How much extra wallpaper should I buy for waste?
You should generally add 10% to 15% extra to your wallpaper order for waste, trimming, and future repairs. If your wallpaper has a large pattern repeat (over 18 inches) or your room has many complex angles and windows, you should increase this to 20%.
What is the standard size of a wallpaper roll?
In the US, a standard single roll of wallpaper is typically 20.5 inches wide and 16.5 feet long (yielding about 28 sq ft). In Europe and the UK, the standard is 53 cm wide and 10 meters long. However, most wallpaper is sold in "double rolls" which are twice as long.
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Reviewed & verified by Ketan Chandore

Technology creator and founder of Pine Tools Hub · Last updated: June 2026

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