Wallsizer computes wallcovering quantities the way a careful installer does: strip by strip, with the pattern repeat, the doors, the windows and the slope of the wall. Everything updates live, and every number on screen matches the drawing and the export.
1
Draw the room
In Walls: widths, heights, doors and windows. Walls unfold left to right.
2
Pick the covering
Wallpaper (Roll, Pattern, Plain) or Mural (Custom, Standard). Each runs its own math.
3
Read the summary
Rolls, strips or murals to order, waste, savings. It updates as you type.
4
Export
PDF for the installer and the client, JPG for a quick send. Add your business name and logo once, in the Export menu: every export carries your branding. Your numbers, on your paper.
Good to know
Units
Toggle cm / in / ft-in any time, top right. Values convert instantly. In ft-in, type 9'6 1/2 for 9 feet 6 and a half inches. A plain number means inches, and fractions alone work too: 6 1/2.
Autosave
Every change is saved on this device, automatically. Nothing is uploaded anywhere.
Projects
The ▾ next to the project name lists your projects: switch, add new, duplicate, delete. Rename by typing over the name.
Undo
The ↺ ↻ arrows, or Cmd/Ctrl+Z. Tab moves you through the fields.
Step 1
Walls
Enter each wall's width and height. Walls sit side by side, left to right, exactly like walking around the room. Wallpaper flows over the corners, so the order of walls matters.
Openings
Add a door, window or niche on its wall. From left is measured from that wall's left corner. Sill is the height of the bottom edge from the floor (doors sit at 0). Rename labels freely: they carry into the export.
Wainscoting
Per wall, height from the floor, 0 means none. The covering stops at the rail, and openings that sit fully inside the wainscot are ignored automatically.
Sloped walls
Switch Sloped walls on in the Project box, then give each wall a left and right height. For a peaked (gable) wall, split it into two walls at the ridge. Strips are cut to the tallest point they cover and the diagonal is trimmed on site.
If an opening pokes outside its wall, Wallsizer outlines it in red and flags it, so a typo never hides in the order.
Wallpaper
Roll
Classic wallpaper sold in fixed rolls. Copy the numbers from the manufacturer label: roll width, roll length, pattern repeat. Wallsizer unrolls your rolls one after another, cuts every strip on a whole repeat, and tells you exactly how many rolls to order and how to cut them.
Pattern match, straight from the label
Labels write the match as two numbers, like 64/32. Wallsizer speaks both languages:
Free (label: 0, "Random match"). No alignment between strips. Each strip is cut at wall height plus overages. The least waste. Typical for solids, textures, plain vinyls.
Straight (label: 64/0). The motif sits at the same height on every strip. Cuts are rounded up to whole repeats, and that rounding is your alignment allowance.
Drop (label: 64/32, "Half-drop"). Every second strip shifts down by half a repeat, so the motif flows diagonally. Wallsizer fits the shift inside the normal rounding when it can, and only charges an extra repeat when it truly does not fit.
Straight: motif level across strips · Drop: every second strip down half a repeat
The fields, in plain words
Side trim
Some materials ship untrimmed: a selvedge edge with printer marks on each side, cut off during install. Enter the loss per edge; usable width becomes roll width minus twice the trim. Normal pre-trimmed rolls: leave 0.
Top / bottom overage
Extra length at the top and bottom of every strip, trimmed on site. Standard practice is about 2 in per end.
Overlap
Most modern wallpaper is butt-seamed: leave 0. Some commercial installs overlap and double-cut; enter the manufacturer's overlap and the strip count adjusts.
Left offset
Slides the design and all seams to the left. Use it to keep a seam off a corner or an opening. The PDF then tells the installer exactly how much to cut off strip 1.
Openings
Optimized: a strip that lands fully on a door or window is cut as short pieces on whole repeats, and short pieces are cut from leftovers of earlier rolls. Full surface: every strip stays full length, maximum safety margin.
Reading the summary
Rolls to order
Physical rolls, consumed in order. If you entered a double-roll length, the count is double rolls.
Waste
How much of the purchased rolls does not end up on the wall, leftovers included. Repeat rounding makes this real, not pessimistic.
Saved by openings
What the optimizer recovered from doors and windows, in rolls or cuts.
Wall area · To cover
Pure geometry: total wall surface, minus openings, equals the surface actually covered. Independent of any toggle.
The cut sheet in the PDF numbers every strip in hanging order, left to right, and marks which roll it comes from and in what order to cut it. The drawing, the numbers and the cut sheet always agree.
Wallpaper
Pattern
Custom-printed wallpaper, made to order. Enter the printed strip width and the vertical repeat of the design tile. Strips are printed at the exact length needed, so you order square footage instead of fixed rolls, and doors and windows save print.
Pattern width
The width of one printed strip.
Pattern height
The vertical repeat of the tile. Pieces align on this grid; a half-drop layout lives in the artwork itself.
Print area
What you order from the printer: cut lengths times strip width, overages included. Shown next to the wall surface so both numbers are in view.
The PDF includes the Install sheet (hanging order: the strips arrive pre-cut) and the Print list, the grouped order for the printer: so many full strips at this length, plus the short pieces, each with its length.
Wallpaper
Plain
No-repeat materials: commercial vinyl, grasscloth, textures, liner. There is no motif to match, so strips are cut at exact length and the commercial unit is the linear yard.
Material width
The width of the goods, for example 54 in commercial vinyl.
Linear to order
The hero number: total length to buy, in linear yards (or meters).
Openings
With Optimized on, both doors and windows save material, because there is no pattern continuity to protect. On Full surface, every strip stays full.
Swatch
Optional texture image, for visualization only. Quantities never depend on it.
Mural
Mural · Custom
A mural printed exactly to your size. Enter the mural's total width and height, slightly larger than the wall surface, then position it with the left and top margins. The right and bottom margins compute themselves.
Coverage
OK means the mural covers the surface with the margins you set. SHORT in red means it does not: the message tells you the maximum margin that still fits.
Panels
Murals ship in vertical panels. Enter panel width and overlap; Wallsizer shows the panel count and the width of the last panel, with a check mark when it fits exactly.
Trim on site
The list under the summary: how much gets trimmed top and bottom, left and right, after positioning.
Mural
Mural · Standard
Some manufacturers sell murals in one fixed size. Wallsizer tiles whole murals side by side across the room: the design repeats at every joint, and you order whole murals.
Whole murals tiled left to right · the design repeats at every joint · excess trimmed on site
Standard mural size
The manufacturer's fixed width and height, from the product page.
Installation margins
Left slides the design and the joints; Top chooses how much of the top is trimmed. Right and bottom compute themselves. The trim list shows all four allowances.
Murals to order
Whole murals, numbered M1, M2 ... on the drawing in hanging order, with panels per mural and the total panel count.
Installer: the left corner falls 140 cm into mural 1: skip panels 1-2, cut 16 cm from the left edge of panel 3, then start level.
When the wall corner falls inside the first mural, the PDF prints a red line like the one above: which panels to skip and where to cut, so the install starts right the first time.
Finish
Exports
The Export button, top right. Every export carries your project name, the date, and the reminder to verify measurements on site.
PDF
The full document: the drawing, the specs, the red installer note when the layout needs one, then the cut sheet (Roll, Plain) or install sheet with the print list (Pattern), plus the layout page with every strip numbered. Murals get a single clean page: panels arrive pre-cut and numbered by the manufacturer.
JPG
One client-friendly image: the drawing with the key numbers under it. Perfect for a quick reply.
Print
The same document through your browser's print dialog, ready for paper or Save as PDF.
Questions
Straight answers
Why does Wallsizer ask for more than an area calculator?
Area calculators divide square footage and hope. Real strips are cut on whole repeats, corners and openings interrupt them, and every cut carries an overage. Wallsizer computes the strips one by one, so the number is the one that actually survives the install.
Single or double rolls?
US wallpaper is often priced per single roll but ships as double rolls. Wallsizer counts physical rolls at the length you enter: type the double-roll length and the count is double rolls.
What exactly is the waste percentage?
The share of the purchased material that does not end up on the wall: repeat rounding, overages, offcuts and roll leftovers, all included. It is measured against the rolls you buy, because that is what you pay for.
Does uploading a design change the quantities?
No. The design upload is visual: it fills the drawing so you can see seams and repeats on the actual artwork. Quantities come from the numbers, always.
What does the red Installer line mean?
It appears when the first strip, panel or mural overhangs the left corner because of an offset. It tells the installer exactly how much to cut from the first piece, so the whole room starts level and on plan.
Coverage says SHORT. Now what?
The mural does not reach the floor or the corner with the margins you set. The red message under the summary tells you the largest margin that still fits, or you can pick a larger mural size.
How do I type feet and inches?
In ft-in mode, type 9'6 1/2 for 9 feet 6 and a half inches. A plain number means inches, and a fraction alone works too. Wallsizer shows fractions to the sixteenth.
Where does my data live?
On your device. Projects autosave locally in your browser; images stay local too. Nothing is uploaded.
A door sits inside the wainscoting. Do I need to do anything?
No. Openings fully inside the wainscot are ignored automatically, because the covering never reaches them. Strips there stay full length and the cut sheet stays sequential.
Can Wallsizer do peaked (gable) walls?
Yes: switch Sloped walls on and split the peaked wall into two walls at the ridge, one rising, one falling. Strips are cut to the tallest point they cover and the pattern grid stays level.