Wallpaper Calculator

Enter your room dimensions and wallpaper roll specifications to find out how many rolls you need. Input your wall width, ceiling height, roll width, roll length, and pattern repeat — the Wallpaper Calculator returns the estimated rolls needed along with total wall area and usable coverage per roll. Adjust for doors and windows to refine your estimate.

ft

Measure the total width of all walls to be wallpapered (room perimeter).

ft
sq ft

Optional: enter the total area of doors and windows you want to subtract.

in

Standard US rolls are typically 20.5 inches wide.

ft

Standard US single rolls are typically 33 ft (11 yards) long.

in

Enter 0 if there is no pattern repeat. Found on the product label.

Extra rolls to account for trimming, pattern matching, and mistakes.

Results

Rolls Needed

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Total Wall Area

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Usable Area Per Roll

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Rolls (Before Waste)

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Wall Area Breakdown

Frequently Asked Questions

How do I measure the total wall width for the calculator?

Measure the width of every wall you plan to wallpaper and add them all together to get the total perimeter. For a standard rectangular room, this means adding the lengths of all four walls. Even if a wall has a door or window, include its full width in the perimeter — you can subtract the door and window area separately in the calculator.

Should I deduct doors and windows from my measurements?

Many professional wallpaper installers recommend NOT deducting doors and windows, as this extra material helps with pattern matching and serves as a buffer for mistakes. However, our calculator gives you the option to subtract a specific square footage if you prefer a tighter estimate. Always order at least 10% extra to be safe.

What is pattern repeat and how does it affect the number of rolls?

A pattern repeat is the distance between where a design motif repeats along the length of the wallpaper. When hanging patterned wallpaper, you must align the pattern across strips, which means some material is cut away and wasted at the top or bottom of each strip. The larger the repeat, the more waste — and the more rolls you'll need.

What size is a standard wallpaper roll?

In the US, a standard single roll is typically about 20.5 inches wide and 33 feet (11 yards) long, covering approximately 56 square feet. European rolls are often 20.5 inches wide and 33 feet long as well, but dimensions vary by brand. Always check the roll dimensions on the product label or page and enter them directly into the calculator.

How much extra wallpaper should I order for waste?

A 10% waste allowance is standard for simple rooms with no or small pattern repeats. For larger pattern repeats, complex room shapes, or if you're a first-time installer, a 15–20% buffer is recommended. Ordering a little extra also ensures you have material on hand for future repairs.

Can I use this calculator for metric measurements?

This calculator uses imperial units (feet and inches). To convert: 1 meter = 3.281 feet, and 1 centimeter = 0.394 inches. Many wallpaper brands, especially European ones, list roll dimensions in meters — simply convert before entering the values.

What if my room has an unusual shape or angled walls?

For irregular rooms, measure each wall section individually and add all widths together for the total perimeter. For rooms with sloped or angled ceilings (like attics), use the average ceiling height. In complex cases, we recommend consulting a professional decorator for a precise estimate.

Is this calculator result an exact number of rolls I need to buy?

The result is an estimate to help guide your purchase. Variations in hanging technique, wall condition, pattern complexity, and installer skill can all affect the final count. We recommend rounding up to the nearest whole roll and adding the suggested waste allowance. Check that all rolls are from the same batch number to ensure color consistency.

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