Calculate rolls, strips and paste for a room, with the pattern repeat priced in.
Room and Roll
Room Length (ft)
Room Width (ft)
Wall Height (ft)
Pattern Repeat (in)
Printed on the roll label. It is the vertical distance between two identical points in the design.
Roll Type
Before you pay
Check every roll carries the same batch number, and ask whether the shop takes sealed rolls back. That answer decides how hard you round up, because a reorder weeks later comes from a different print run.
Estimates only. Not professional advice.
Rolls to buy
8US Double Rolls
Enough to cover 381 sq ft of net wall at 10% waste with no repeat to match.
Paper only. Paste is figured at one gallon per four rolls, and primer, sizing, a seam roller and a smoothing brush are not counted.
Strip cuts
Wallpaper is not an area calculation. Every strip has to start at the same point in the design, so a cut is only allowed on a repeat boundary, and the drop gets rounded up to whole repeats before it ever leaves the roll. That is why a roll that covers 56 sq ft on paper can hand you one strip fewer than you counted on. Nothing here changes your order above.
Length and width share one scale, so the roll really is that shape. Only the tail of the roll is hatched, and that is the piece left over after the last full strip. A random match needs no alignment, so no strip loses a slice to the pattern, which is the cheapest case wallpaper has.
8 rolls cut into 32 usable strips against the 32 the walls need, so the area figure holds here exactly, with nothing spare.
The offcut starts on a repeat boundary, the same point in the design every strip starts at, so it drops straight in above an opening. Each one covers the 12 in above a 7.0 ft door once.
Cut schedule
Four rooms
Four jobs run through this calculator at its 10% waste setting, on US double rolls. Rooms two and three are the same bedroom, and the only thing that changes is the repeat.
6 × 5 ft · 8 ft ceiling · 1 door · random match
4 rolls · 13 strips
155 sq ft net, ordered at 171. A random match means no repeat to align, so each roll gives four full drops and the whole order is bought on area alone. Small rooms take bold patterns well, and there is only one seam anybody stands close to.
15 × 12 ft · 8 ft ceiling · 1 door, 2 windows
8 rolls · 32 strips
381 sq ft net, ordered at 419. Four strips out of every roll and 32 strips needed, so eight rolls lands exactly. Exactly is not comfortable: one bad cut and you are back at the shop chasing a dye lot.
15 × 12 ft · 8 ft ceiling · 1 door, 2 windows
9 rolls by area, 11 by strip
The 96 in drop rounds up to 108 in, so each roll yields three strips instead of four and 12 in of every strip goes in the bin. The 20% band takes the area figure to nine rolls, but 32 strips at three per roll needs eleven. This gap is the reason this page exists.
20 × 15 ft · 9 ft ceiling · 2 doors, 4 windows
13 rolls by area, 14 by strip
528 sq ft net, ordered at 686. A 108 in drop divides into nine whole 12 in repeats, so nothing is trimmed off each strip, and the waste all lands in one 72 in offcut per roll instead. That offcut clears the 24 in above a 7 ft door six times over.
Areas above are imperial because they are worked examples, not live figures. Switch the calculator to metres and your own readout follows.
Written and reviewed by
Creator
Cherry Jane Limbago
Licensed Civil Engineer & Master Plumber
Licensed civil engineer and master plumber with 10+ years in structural design, estimation, and project management. Currently Project Engineer at Universal Robina Corporation.
See full profileExpert Review
Hawkin
Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
See full profileUpdated August 5, 2026
How we verify our calculatorsRounding rules
Per roll
Paper is priced by the roll, not by the square foot, which is why two rooms of the same size can differ fourfold. The right-hand column is your own roll count at each grade.
| Grade | Per roll | Your 8 rolls |
|---|---|---|
| Budget Vinyl | $15 – $30 | $120 – $240 |
| Mid-Range Paper | $30 – $60 | $240 – $480 |
| Premium Non-Woven | $50 – $100 | $400 – $800 |
| Grasscloth/Textured | $80 – $180 | $640 – $1,440 |
| Designer/Custom | $100 – $300 | $800 – $2,400 |
Ranges are per double roll, the US standard. A single roll holds half the length, so a single-roll order is costed at half these figures per roll. The headline range in the calculator uses the mid-range band, $30 to $60 a roll.
Drop to rolls
Perimeter times height gives the wall area, openings come off it, and the waste slider plus the repeat band are added to what is left. Dividing by the coverage of one roll and rounding up gives the roll count. The repeat band is added to your waste setting rather than replacing it, so a 12 inch repeat at 10% waste is ordered at 30%.
The strip count is a separate calculation, and it uses the perimeter and the roll width rather than area, because a strip is a fixed width whatever the wall behind it is doing. Openings do not reduce it: you still hang a strip past a window and cut the middle out. That is also why the two numbers disagree, and the cut plan above is where the disagreement gets settled.
Two things the arithmetic cannot see. The strip figure works off the perimeter as one continuous run, so it does not add the part strip that every internal corner forces, and it does not know your walls are not plumb. Both push the real count up rather than down, which is the argument for buying the spare roll while the print run is still on the shelf.
The formulas
perimeter = 2 × (L + W)wall = perimeter × Hnet = wall − doors×21 − windows×15order = net × (1 + waste + repeat)rolls = order ÷ roll coveragestrips = perimeter ÷ roll widthpaste = rolls ÷ 4Openings are deducted at 21 sq ft per door and 15 sq ft per window. Every division rounds up, because half a roll is not a thing you can buy.
Paper shop
The eight things people ask before they hand over a roll count, answered against the same WIA and maker guidance this calculator is built on.
About 8 to 10 double rolls with standard 8-foot ceilings, 1 door, and 2 windows with 10% waste.
Double rolls are standard in the US market. They have twice the length (33 ft vs 16.5 ft) and waste less per strip.
The distance between identical points in the wallpaper pattern. A 12-inch repeat means every 12 inches the pattern starts over. Larger repeats waste more material.
About 1 bucket (gallon) per 4 double rolls. Pre-pasted wallpaper needs only a water tray.
Not recommended. Remove existing paper, repair the wall surface, prime with wallpaper primer, then hang new paper.
Measure the perimeter of the room (all walls), multiply by ceiling height. Deduct 21 sq ft per door and 15 sq ft per window.
A US double roll (33 ft long, 20.5" wide) yields about 3 to 4 full strips for 8-foot walls, depending on pattern repeat.
Yes. Use a wallpaper-specific primer (not regular paint primer). It helps the paste adhere and makes future removal easier.
Pattern match
The roll label tells you the repeat and the match. The repeat sets how much gets trimmed off each strip; the match sets how the strips relate to each other, and therefore how much of the roll you can plan around.
| Match | What has to line up | Waste added |
|---|---|---|
| Random match | Nothing. The design carries across the seam at any height, so a strip can start anywhere on the roll. | +0% |
| Straight match | Every strip starts at the same point in the repeat, so the design runs level across the wall from one seam to the next. | +10% or +20% |
| Drop match | Alternate strips are hung half a repeat lower, so odd and even strips are cut from two different starting points and the wall repeats vertically over two repeats, not one. | +10% or +20% |
This calculator carries three waste bands and picks between them on repeat length alone: nothing for a random match, 10% up to 6 inches and 20% above it. It does not hold a separate figure for a drop match, so treat the band as a floor there and buy a spare roll on top. A drop match also has to be hung in strict order, since the offcut from an odd strip starts on the wrong half of the repeat for the next odd strip.
Roll label
Four lines on the label decide the whole order, and three of them are the ones people skip.
Hanging order
Numbered because the sequence is the point. Each one is settled before the step after it, and none of them can be revisited once the paste is on the wall.
Buy the whole job in one order and check that every roll carries the same batch or dye lot number. Two lots of the same paper can differ enough in shade to read as a stripe down one wall.
Hang a plumb line for the first strip on every wall, not just the first wall. Corners are rarely square, so an out-of-plumb start compounds across every strip after it.
Start at the most visible corner and work away from the main window. The last seam of a run is the one that never quite closes, so put it where the light does not rake across it.
Cut all the strips for one wall before you paste any of them, and lay them face up in hanging order. Cutting as you go is how strips get hung out of sequence on a drop match.
A repeat over 6 inches puts this calculator into its 20% band, and the offcut at the end of each roll grows with it. Check whether that offcut clears your door heads before you decide how hard to round up.
Book the paper, meaning fold it paste to paste, for the time the maker states. Skipping it is why seams open a week later as the paper finishes shrinking on the wall.
Prime with a wallpaper primer or sizing rather than paint primer, and patch the wall first. Our drywall calculator sizes sheets and compound if the surface needs more than filler.
Trim and ceilings are painted before the paper goes up, not after. The paint calculator covers that side of the room.
Peels and seams
None of these show on the day you finish. They show up a fortnight later, and every one of them was decided before the first strip was cut.
Ordering by area and ignoring the strip count
Area divides cleanly. Rolls do not, because a strip has to be a whole number of repeats and the tail of the roll is usually too short to be another one.
Work out strips per roll from your own wall height and repeat, then order on whichever number is higher. The cut plan above does both.
Buying rolls from two different runs
Shade drifts between print runs, and it shows worst on textured and natural fibre papers where the base itself varies.
Order the whole job at once, check the batch number on every roll, and keep one sealed roll back for repairs rather than trusting a reorder.
Starting the first strip off the door casing
Casings and corners are almost never plumb, so the pattern leans further with every strip and the last seam on the wall shows it.
Snap or hang a plumb line for the first strip on each wall, and accept that the strip beside the door may need trimming to suit.
Hanging over old paper or bare new drywall
Old paper releases when the new paste wets it, and untreated drywall grabs so hard the facing tears when the paper ever comes off.
Strip the old paper, fill and sand, then prime with a wallpaper primer or sizing. That coat is what makes removal possible later.
Cutting strips as you hang them
On a drop match the strips alternate between two starting points, so cutting one at a time gets them out of sequence and the seam stops matching.
Cut and number every strip for a wall before pasting any of them, and lay them out in hanging order.
Skipping the booking time
Paper expands while it is wet and shrinks as it dries. Hung too early it is still growing, and it pulls the seam open as it settles.
Fold the pasted strip paste to paste and leave it the time the maker states, then hang it. Do the same for every strip so they all move alike.
Disclaimer
These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.
Sources