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Wallpaper calculator

Work out how many rolls of wallpaper you need. Enter the total wall length around the room, the height, and the pattern repeat if there is one, and this calculator gives you the number of standard rolls, allowing for trimming and pattern matching.

Wallpaper calculator

Enter your measurements in metres. Everything updates as you type, and nothing is sent anywhere.

Based on a standard UK roll of 10.05m long and 0.53m wide, with about 100mm added to each drop for trimming top and bottom, plus the pattern repeat you enter. Doors and windows are not deducted, which builds in a sensible safety margin, since part-width and offcut drops rarely reuse cleanly. Buy all your rolls from the same batch number.

Put this calculator on your site

This calculator is free to add to your own website, blog or client resources. Copy the code below and paste it into a page. It keeps a small credit link back to Costwise, and the figures stay exactly as they are here.

Common questions

How many rolls of wallpaper do I need?

Work out how many full drops your roll gives (a 10.05m roll divided by your wall height plus trim and pattern repeat), then how many drops go round the room (the wall length divided by the 0.53m roll width), and divide one by the other. The calculator does it for you.

How does the pattern repeat change how much I need?

A large pattern repeat wastes paper, because each drop has to start at the same point in the pattern, so you lose up to a full repeat off every drop. Enter the repeat from the roll label and the calculator allows for it. A free-match or random pattern wastes the least.

Should I deduct doors and windows?

It is safer not to. Offcuts from around a door or window rarely give you a clean full-height drop elsewhere, so most decorators paper as if the wall is solid and keep the offcuts for the over-door and under-window pieces. This calculator does the same, which leaves a small margin.

These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing. These quantities are a guide to help you order. Always round up and check with your supplier before buying.