How Much Extra Wallpaper Should You Order for a Mural?

“Extra wallpaper” can mean three different things for a mural: a fitting margin at the wall edges, a complete replacement panel, or more artwork for a wall with an unusual outline. Only the first is covered by the standard size allowance. Solowalls asks for about 4 inches (10 cm) added once to the maximum wall width and once to the height. A larger number typed into the order form does not create a labelled spare panel, and it may change the artwork crop.

Start with six measurements, not a guess about waste

Take width readings near the ceiling, at mid-height and just above the skirting. Take height readings at the left, middle and right. A wall might be 298, 300 and 299 cm wide, and 241, 242 and 240 cm high. In that example the maximum wall rectangle is 300 by 242 cm. The smaller readings remain useful: they tell the installer where trimming is likely to be needed. Ordering from an average or from a single convenient point can leave a gap at the widest or tallest location.

Do not reduce the width because a cupboard hides part of the wall. If the mural is meant to run corner to corner, the print must cover that full span. Likewise, do not deduct the area of a window from the width and height of a continuous mural. The image normally needs to align on both sides of the opening. Separate the question of print area from the question of how much of the artwork will remain visible after furniture and openings are considered.

Keep two numbers in your notes: the maximum finished-wall rectangle and the larger size entered for printing. The Solowalls form asks you to add the allowance yourself. If you later order from a different seller, read its own wording; some production workflows add trim after customers submit the finished-wall dimensions. Do not transfer that other workflow to this checkout or add the same margin twice.

Worked example in centimetres

Suppose the widest measurement is 300 cm and the tallest is 242 cm. If the seller instructs you to add 10 cm to each overall dimension, the order dimensions are 310 by 252 cm. That provides 10 cm of extra width in total and 10 cm of extra height in total; it does not promise 10 cm on each of four edges. The available trim on any one edge depends on how the print is positioned during fitting. Entering 320 by 262 cm instead would add 20 cm to each overall dimension and could change the crop of a proportional design.

On Solowalls, enter the approximately 310 by 252 cm print size in that example, then review the crop before buying. The additional area may affect price and the part of the image shown in the preview. If another seller explicitly asks for finished-wall size and adds trim in production, its form may instead take 300 by 242 cm. These are different workflows, not two alternative answers for the same order.

For a very small feature area, a fixed allowance occupies a larger share of the print than on a wide wall. For an unusually irregular outline, the ordinary allowance may not cover every edge after alignment. These are reasons to show the actual dimensions and shape to the supplier or installer, not to invent a universal waste percentage.

Worked example in inches

Imagine a wall that measures 119 inches wide at its widest point and 96 inches high at its tallest. If the order instructions say to add 4 inches to total width and total height, enter 123 by 100 inches. That is different from adding 4 inches on every edge and entering 127 by 104 inches. Keep the unit visible on your written order notes. A number copied from an inch measurement into a centimetre field is a far bigger error than a modest difference in trimming allowance.

Some forms round to whole units; others accept decimals. If your maximum width is 118.6 inches, do not round down to 118. Ask how the seller handles fractional dimensions or round conservatively according to the form’s instructions. Measure again if the result seems inconsistent with the room. A second person holding the tape can eliminate a sagging or diagonal measurement on a wide wall.

When switching between units, use one conversion method and keep the original readings. Rough equivalents such as 4 inches and 10 cm are helpful for planning, but they are not mathematically identical. The checkout’s chosen unit and stated allowance should govern the final order. Avoid converting back and forth several times and accidentally adding the margin on each conversion.

When “extra” means something other than trim

You may also be thinking about damage during installation or a future repair. The outer trim strips are usually narrow and may contain only fragments of the scene. They can help with a small test or touch-up but cannot replace a full-height damaged panel. If a spare matters—for example, where furniture will repeatedly strike one part of the wall—ask before ordering whether the supplier can provide a complete extra panel from the same print run, which panel it would be, and what it would cost. Availability is not automatic. A replacement ordered much later may differ in colour or alignment, and adding 20 cm to the overall width does not create a usable spare panel.

Standard repeating wallpaper is calculated differently. Its pattern repeat, roll width, wall height and number of drops determine waste. A panoramic mural printed for a specific wall does not automatically need the same percentage allowance used for repeat rolls. Conversely, a design sold as fixed-size panels may have limited flexibility. Read the product format before applying a calculation found for another type of wallcovering.

Installation around a staircase, deep alcove or heavily sloped ceiling may require a bespoke layout. A rectangular allowance alone cannot describe those shapes. Send a labelled drawing with dimensions for each plane and ask how much print area the supplier recommends. If you are hiring an installer, have them verify the measurement before the file is approved for production.

Check the order before approving the crop

Place the measured wall rectangle, the larger entered print size and the selected crop side by side before paying. Check that the units and one-time allowance agree with your notes, then save the accepted preview for the installer. If the preview no longer keeps the main subject inside the finished-wall boundary, adjust the composition before placing the order; surplus material cannot restore artwork already cropped away.