About
Why we built a wallpaper calculator that isn't a calculator
Every roll-count tool multiplies wall area by roll size and calls it a plan. That number is often wrong — and it's wrong in the direction that costs you a second trip to the shop.
The problem with perimeter × height
An ordinary calculator adds up your wall area, divides by what a roll covers, and rounds up a little for luck. It has no idea what pattern you've picked, doesn't know a stairwell isn't a rectangle, and can't say where a seam actually falls. On the raked stairwell in our own worked example, that shortcut asks for 21 rolls where the real cutting plan only needs 11. On a plain room with a 64cm half-drop repeat, the ordinary method comes up four rolls short even with its usual ten per cent safety margin added on.
What the planner actually does
Draw your walls to their real dimensions, choose your paper, and the planner places every seam, works out where the pattern repeat forces a cut, and solves for the smallest number of rolls that actually covers the job — the same cutting-stock problem a professional works out by hand, done properly. It checks its own answer against what an ordinary calculator would have said on your own walls, and shows the method it compared against rather than a single, assumed number.
Built to be checked, not trusted blind
The plan says when it's provably the minimum number of rolls, and when it's the best solution found rather than proven — never one dressed up as the other. The free tier applies the same repeat rounding and roll-head allowance as the paid plan, so a free estimate is safe to actually order from. What you pay for is the exact cutting plan and printable worksheets, not a safer number.
Who it's for
Two kinds of people use it. Someone papering one room who wants the roll count right the first time and never needs the tool again — that's free, for drawing and the estimate. And decorators and contractors who plan wallpaper jobs every week and need the cutting plan, printed worksheets, and multi-room estimating fast — that's the paid side.
A note on why this exists
The first version of this got built standing in a stairwell with a part-used roll of patterned paper, working out by hand where the next cut needed to fall so the pattern kept lining up down a sloped ceiling — while the calculator that had sold the roll count in the first place had no idea any of that mattered. It just multiplied a perimeter by a height. Wallpaper Planner is the tool that was missing at that point: one that draws the actual seams and cuts before you buy, not after.
Try it on your own room
Draw your walls for free — pay only if you want the exact cutting plan and worksheets.
Open the calculator See plans & pricingCompany, VAT and contact details are kept on the terms & seller information page so they never fall out of sync with an invoice.