Wallpaper Calculator
Calculate how many rolls of wallpaper you need — enter your room size, roll dimensions, and pattern repeat.
Room Dimensions
Enter your room dimensions and click Calculate.
How Does the Formula Work?
Calculating wallpaper starts with the room perimeter: 2 × (length + width). Divide this by the strip width — usually 20.5 inches in the US or 53 cm in Europe — to get the total number of strips needed to wrap the room.
Next, deduct strips for openings: each standard door removes about one strip width, and each window about half a strip. This gives the net strips — the actual number of strips you need to cut and hang.
The drop length determines how many strips you can cut from one roll. It equals the wall height plus any pattern repeat. A standard European roll is 10.05 m long. If your walls are 2.50 m and the pattern repeats every 32 cm, your drop length is 2.82 m — giving you 3 strips per roll (10.05 ÷ 2.82 = 3.56, rounded down).
Pattern repeat is the key variable most people miss. Plain wallpaper has zero repeat and produces minimal waste. A 64 cm repeat on short walls can cut your strips-per-roll in half, doubling the number of rolls you need. Always check the repeat on the label before buying. Popular brands like Graham & Brown, Cole & Son, and York Wallcoverings print the repeat on every roll.
Waste and Extras
We recommend buying one extra roll beyond the calculated amount. Wallpaper dye lots vary between production runs, so having a spare from the same batch is essential for future repairs. Unused, unopened rolls can usually be returned.
Wallpaper Types and Materials
Modern wallpaper comes in several material types, each with different durability, application methods, and price points. Vinyl wallpaper is the most durable and moisture-resistant option, ideal for kitchens and bathrooms — brands like York Wallcoverings, Brewster, and Graham and Brown dominate the US market. Non-woven (fleece) wallpaper has a fabric-like backing that makes it paste-the-wall rather than paste-the-paper, significantly simplifying installation. Pre-pasted wallpaper from brands like RoomMates and NuWallpaper is activated with water and requires no separate adhesive. Peel-and-stick wallpaper (removable) has become enormously popular for renters and DIY projects — it applies like a giant sticker and removes cleanly. Traditional paper-backed wallpaper requires paste-the-paper application and is favored for its print quality. Grasscloth and textile wallpapers are premium options costing $50–$200 per roll. At Home Depot and Lowe's, standard vinyl rolls cost $25–$60, while designer collections from Rifle Paper Co., Hygge and West, or Schumacher run $75–$200 per roll.
Understanding Roll Dimensions
US standard wallpaper rolls are 20.5 inches wide and 33 feet long, covering approximately 56 square feet before accounting for waste. European rolls are typically 21 inches (53 cm) wide and 33 feet (10.05 meters) long, yielding about 57.75 square feet. Some commercial and specialty wallpapers come in 27-inch widths or double rolls (covering about 72 square feet). The calculator uses your specific roll dimensions to compute coverage accurately. Always verify the roll width and length printed on the packaging — dimensions vary between manufacturers and product lines.
Pattern Repeat and Waste
Pattern repeat is the distance between identical points in a repeating design. A 12-inch repeat means the pattern restarts every 12 inches. This affects waste because each strip must be aligned to the pattern, often requiring you to cut away several inches (or even a foot) of paper at the start of each strip. A random match (no pattern alignment needed) has zero waste from repeats. A straight match aligns horizontally at the same point — moderate waste. A half-drop match offsets the pattern by half the repeat on alternating strips — the highest waste, sometimes up to 25 percent. The calculator factors in your pattern repeat to adjust the number of usable strips per roll, giving you a realistic roll count rather than a theoretical minimum.
Surface Preparation
Proper wall preparation is critical for wallpaper adhesion and appearance. Walls must be smooth, clean, dry, and primed. Fill any holes, dents, or cracks with spackling compound and sand smooth. Apply a wallpaper-specific primer like Zinsser Shieldz or Roman PRO-977 Ultra Prime — these create a surface that accepts paste evenly and allows future wallpaper removal without damaging the drywall. Never hang wallpaper over glossy paint without sanding and priming first. New drywall must have at least two coats of paint or primer before wallpapering. Textured walls (orange peel, knockdown) should be skim-coated smooth — wallpaper will not hide texture and will develop bubbles over high spots.
Installation Tips
Start hanging from a vertical plumb line near the least visible corner of the room (usually behind the entry door). Use a 4-foot level or laser level to mark a perfectly vertical starting line — walls are rarely plumb. For paste-the-wall application (non-woven wallpaper), roll adhesive directly onto the wall with a short-nap roller. For paste-the-paper types, use a pasting table and book the paper (fold paste-to-paste) for 5 minutes to allow expansion before hanging. Smooth each strip from the center outward with a plastic smoother or wallpaper brush, pushing out air bubbles. Overlap the first and last strips at the starting corner and double-cut through both layers with a sharp utility knife for a perfect seam. Trim top and bottom edges with a broad knife and fresh razor blade.
How Many Rolls to Buy
This calculator computes net wall area (total wall area minus doors and windows), then divides by the usable coverage per roll after accounting for pattern repeat waste. The result is rounded up to whole rolls. Always buy one to two extra rolls from the same dye lot — wallpaper batches can vary slightly in color, and having extra ensures you can make repairs or cover mistakes. Unopened rolls from Home Depot and Lowe's can be returned within 90 days. Keep the lot number written on the packaging for reference.
Cost Comparison
Wallpaper costs vary dramatically by material and brand. Budget peel-and-stick starts at $20 per roll ($0.35/sq ft). Mid-range vinyl runs $30–$60 per roll ($0.52–$1.05/sq ft). Designer collections reach $75–$200 per roll ($1.30–$3.50/sq ft). Professional installation adds $1–$3 per square foot. A typical 12×14-foot bedroom with 8-foot ceilings requires 8–10 rolls — material cost ranges from $200 for budget options to $1,500 for designer paper. DIY installation saves $300–$900 in labor but requires a pasting table ($25), seam roller ($8), smoother ($10), and a very sharp utility knife. This calculator helps you determine the exact number of rolls so you can budget accurately before visiting the store.
Understanding Wallpaper Roll Sizes
In the United States, a standard single roll of wallpaper measures 20.5 inches wide and 33 feet long, covering approximately 56 square feet. However, wallpaper is almost always sold in double rolls which yield about 56 to 72 usable square feet depending on the pattern. European rolls are typically 53 cm wide and 10 meters long. Grasscloth and specialty wallpapers from brands like Phillip Jeffries, Thibaut, and Schumacher may come in non-standard widths of 36 or 54 inches. Always check the specific roll dimensions on the label before calculating.
Pattern Repeat and Waste
Pattern repeat is the distance between identical points in the design. A wallpaper with a 12-inch repeat means the pattern cycles every 12 inches vertically. This matters because each strip must be aligned to the previous one, which creates waste at the top and bottom. A straight match aligns the pattern at the same height on adjacent strips — waste equals up to one full repeat per strip. A drop match shifts the pattern by half a repeat on alternating strips, potentially doubling the waste. Random-match wallpapers like textures and grasscloth have no repeat and generate minimal waste. The calculator accounts for pattern repeat by adding waste to each strip.
Types of Wallpaper
Vinyl wallpaper is the most durable and washable, ideal for kitchens and bathrooms. Brewster, York, and Graham and Brown offer peel-and-stick vinyl that requires no paste and is removable, perfect for renters. Non-woven wallpaper is applied by pasting the wall instead of the paper, making it easier to hang. Traditional paper wallpaper offers the widest luxury designs but is harder to install. Grasscloth adds organic texture but is not washable. Pre-pasted wallpaper has dry adhesive that activates with water — convenient but less reliable than paste-the-wall methods.
Measuring and Cutting
Measure your wall height from floor to ceiling and add 4 inches for trimming. Divide the wall width by the wallpaper width to find the number of strips per wall. Multiply the number of strips by the cut length (wall height plus trim plus pattern repeat waste) to find total linear footage. Divide by roll length to get the number of rolls. Always round up to whole rolls — wallpaper from the same dye lot ensures color consistency, and leftover wallpaper is useful for repairs.
Installation Tips
Prepare walls by filling holes, sanding rough spots, and applying a wallpaper primer like Zinsser Shieldz. Use a plumb line or laser level to mark a perfectly vertical starting line. Apply adhesive evenly using a paint roller for paste-the-wall papers. Smooth each strip with a wallpaper brush, working from center to edges to push out air bubbles. Overlap strips by a quarter inch at seams and double-cut through both layers for a perfect butt joint. Use a sharp blade and change it frequently, as a dull blade tears wet wallpaper.
Cost and Ordering
Wallpaper prices range dramatically. Basic vinyl from Brewster or NuWallpaper costs 20 to 40 dollars per double roll. Mid-range designs from York, Magnolia Home, and Rifle Paper Company run 50 to 100 dollars. Designer wallpaper from Farrow and Ball or Cole and Son can exceed 200 dollars per roll. For a standard 12 by 14 foot bedroom, you typically need 8 to 10 double rolls. At mid-range prices, that is 400 to 1000 dollars for materials. Professional wallpaper hanging costs 40 to 75 dollars per roll. Always buy one extra roll from the same dye lot for mistakes and future repairs.
Tips & Recommendations
Patterned wallpaper wastes more per strip. A 64 cm repeat can double your roll count compared to plain. Always verify the repeat on the label.
Dye lots vary between batches. An extra roll from the same batch saves you if a strip tears or you need repairs later.
Walls are rarely perfectly plumb. Measure height at multiple points and use the tallest measurement as your wall height.
Fireplaces, built-in shelves, and alcoves may need partial strips. Add one extra roll if your room has unusual features.
Frequently Asked Questions
How many rolls of wallpaper do I need for a 12×12 ft room?
A 12×12 ft room has a 48 ft perimeter. With 20.5-inch-wide rolls, you need about 28 strips. At 8 ft walls with no pattern repeat, a 33 ft roll gives 4 strips each. After deducting a door and two windows (about 2 strips), you need roughly 26 strips ÷ 4 = 7 rolls. Add one spare for safety.
What is pattern repeat and why does it matter?
Pattern repeat is the vertical distance between identical points in the wallpaper design. When hanging, you must align the pattern across strips, which means cutting extra from each drop. A 64 cm repeat on 2.5 m walls wastes about 50 cm per strip, reducing the strips you get per roll from 4 to 3 — increasing your total roll count by 25–33%.
Does the calculator deduct for doors and windows?
Yes. Each door removes approximately one full strip width and each window about half a strip from the total count. This prevents over-buying while leaving a small safety margin for trimming around frames.
What is a standard wallpaper roll size?
In Europe and Turkey, the standard roll is 0.53 m wide × 10.05 m long. In the US, a single roll is 20.5 inches wide × 33 feet long, though most stores sell double rolls (20.5 in × 66 ft). Always check the label for the exact dimensions of your chosen product.
Should I buy extra wallpaper?
Yes, always buy at least one extra roll from the same dye lot. Colour can vary between production batches, making it difficult to match later. Unopened rolls can typically be returned to the store.
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