Free Wallpaper calculator
Turn your room into a wallpaper order the right way: wall area minus openings, divided by the usable coverage of one roll — with the waste a pattern repeat adds and a trim margin built in. Pick US single, double, or Euro rolls and a free, straight, or drop match to see the roll count updated live, as you type.
On this page15 sections
| Roll type | Rolls | Est. cost |
|---|---|---|
| US single | 16 | $608 |
| US double | 8 | $512 |
| Euro / metric | 11 | $605 |
Prices are regional estimates: single ≈ $38, double ≈ $64, Euro ≈ $55 per roll. A double roll is two singles in one length, so it usually needs fewer rolls and less waste. Buy all rolls in one dye lot.
Roll length and pattern repeat vary by paper. How accurate is this?
Results are estimates. Consult a professional.
How the wallpaper calculator works
Wallpaper is sold by the roll, not by the square foot, so the whole job is turning your wall area into whole rolls. The calculator multiplies the perimeter of the walls you are papering by the ceiling height to get the gross area, subtracts the doors and windows, then divides by the usable coverage of one roll. The catch is that "usable" is well below the roll's printed area, because pattern matching and top-and-bottom trimming throw some of every roll away.
What the roll count really means
The roll count is the number you take to the till — and the number you must get right in one order. Wallpaper is dyed in batches, so a roll bought next week can be a slightly different shade than the ones bought today. That is why the calculator rounds up and adds a trim margin: a leftover roll is cheap, but running one roll short can mean a visible seam in a different dye lot, with no clean way to fix it.
What goes into your wallpaper estimate
A wallpaper estimate is built from four pieces. Two are fixed by your room. Two are choices you make at the store, and they move the roll count more than people expect.
Wall area — the base number
Perimeter times ceiling height, minus the openings. Add the widths of every wall you are papering to get the perimeter, multiply by the floor-to-ceiling height, then subtract the area of the doors and windows. This is the geometry, and it is the part the calculator nails exactly.
Roll type — how much each roll covers
A US single roll covers about 36 square feet on paper; a US double roll is the same paper at double the length, about 72 square feet, and is how most American wallpaper is sold. European and most peel-and-stick rolls run 52 cm by 10 m, roughly 56 square feet. Pick the wrong roll type in the calculator and the count is off by half.
Pattern repeat — the hidden waste
To line up the design across seams, you trim the top of each new strip to match its neighbor, and that offcut is waste. A plain or free-match paper loses about 10%; a straight match about 15%; an offset or drop match about 20%; a big repeat can eat 25% or more of every roll. This is the single biggest reason a square-foot estimate comes up short.
Trim margin — the safety net
On top of pattern waste, you lose a few inches trimming each strip at the ceiling and baseboard, plus the odd mis-cut around a switch or a window. A 10% margin covers it. The calculator adds 10% by default and lets you adjust it.
A worked example using the wallpaper calculator
Maya is papering all four walls of a 12 ft × 14 ft bedroom with a 9 ft ceiling. The room has one door and one window, and she has chosen a straight-match paper sold in US single rolls. She wants the roll count for a single order in one dye lot.
Step 1 — Find the wall area
Perimeter is 2 × (12 + 14) = 52 ft. Times the 9 ft ceiling, that is 468 ft² gross. The door (about 21 ft²) and window (about 12 ft²) total 33 ft², so the net wall area is 468 − 33 = 435 ft².
Step 2 — Find the usable coverage per roll
A single roll is 36 ft² nominal. A straight match wastes about 15% to pattern trimming, so 36 × (1 − 0.15) = 30.6 ft² usable per roll.
Step 3 — Divide and round up
435 ÷ 30.6 = 14.2 rolls. You can't buy a fraction of a roll, so round up to 15 single rolls as the bare count.
Step 4 — Add the trim margin
With a 10% trim margin for ceiling and baseboard cuts, 14.2 × 1.10 = 15.6, rounded up to 16 single rolls. In double rolls — the way it is usually stocked — that is 8 double rolls.
How many rolls of wallpaper do I need?
If you want a ballpark before you measure precisely, this table gives single rolls for common room sizes at a 9 ft ceiling and a straight-match pattern. To stay on the safe side it does not subtract doors and windows — many installers leave the openings in, because you still paper above and below them and the offcuts rarely fill another strip. Confirm with your own measurements before ordering.
| Room (9 ft ceiling) | Perimeter | Wall area | US single rolls |
|---|---|---|---|
| 10 ft × 10 ft | 40 ft | 360 ft² | 12 |
| 12 ft × 12 ft | 48 ft | 432 ft² | 15 |
| 12 ft × 14 ft | 52 ft | 468 ft² | 16 |
| 14 ft × 16 ft | 60 ft | 540 ft² | 18 |
| 16 ft × 20 ft | 72 ft | 648 ft² | 22 |
Single rolls at 36 ft² nominal and a 15% straight-match waste (30.6 ft² usable), openings not subtracted. Halve the count for double rolls. A larger pattern repeat needs more; see the next section.
Single, double, and Euro rolls explained
The most confusing thing about ordering wallpaper is that it is priced one way and sold another. In the US, paper is priced per single roll but almost always packaged and sold as double rolls — one continuous length that is two singles joined. Knowing which unit a price refers to keeps you from doubling or halving your order by mistake.
| Roll type | Typical size | Nominal area | Usable (straight match) |
|---|---|---|---|
| US single roll | ≈ 20.5 in × 16.5 ft | 36 ft² | 30.6 ft² |
| US double roll | ≈ 20.5 in × 33 ft | 72 ft² | 61.2 ft² |
| Euro / metric roll | 52 cm × 10 m | ≈ 56 ft² | 47.6 ft² |
Nominal area is the printed coverage. Usable figures apply a 15% straight-match waste; a larger repeat lowers them further. US widths are commonly 20.5 in or 27 in; metric and peel-and-stick rolls are usually 52 cm (≈ 20.5 in) wide.
A double roll is not extra wallpaper — it is the same paper in one longer piece, which means fewer seams and less waste than buying two singles, because you cut more full strips before reaching an offcut. When a designer paper is quoted "per single roll" but only sold in doubles, the price you pay at checkout is for two. The same fixed-width logic governs the carpet calculator, where buying off a 12 ft roll drives the waste.
Pattern repeat and match types: the hidden waste
Square-foot math tells you the area. It does not tell you how much paper you throw away making the design line up — and that is where most short orders come from. The pattern repeat is the vertical distance before the design starts over, printed on every roll's label, and the match type decides how strips align side by side.
The three match types
- Free match — no alignment needed between strips, so almost nothing is wasted. Common on textures, grasscloths and faux-wood designs. Budget about 10%.
- Straight match — the design lines up straight across, edge to edge, on every strip. You trim each strip to the same start point. Budget about 15%.
- Drop (offset) match — the design only lines up when each strip is dropped by half a repeat, so alternate strips start differently. Budget about 20%, and more on big repeats.
| Match type | Single roll usable | Double roll usable | Euro roll usable |
|---|---|---|---|
| Free match (10%) | 32.4 ft² | 64.8 ft² | 50.4 ft² |
| Straight match (15%) | 30.6 ft² | 61.2 ft² | 47.6 ft² |
| Drop match (20%) | 28.8 ft² | 57.6 ft² | 44.8 ft² |
| Large repeat (28%) | 25.9 ft² | 51.8 ft² | 40.3 ft² |
Usable coverage per roll by match type, before the trim margin. A single roll at a large repeat yields about 25.9 ft² — the 25–27 ft² figure US suppliers quote — versus 32.4 ft² free-match. That gap is whole rolls on a big room.
Do I subtract doors and windows?
It depends on how careful you want to be, and many professionals deliberately do not. You still paper above a door and above and below a window, and the strips you cut around an opening leave offcuts too small to use elsewhere, so the "saved" area rarely turns into a saved roll.
The safe default: leave them in
For a quick, safe estimate, treat each wall as solid from corner to corner and floor to ceiling, openings included. You will buy a little extra, which is exactly what you want when a missing roll means a dye-lot mismatch.
When to subtract
On a room dominated by glass — a wall that is mostly patio doors or a big picture window — leaving the openings in can over-order by a roll or two. There the calculator lets you subtract them: a standard door is about 21 ft² and a typical window 9–15 ft². Enter the total opening area and it comes out of the wall area before the roll count. The same wall-area step drives the drywall calculator if you are boarding the room before you paper it.
Why dye lots mean you should over-order
Wallpaper is printed in batches, and each batch — its dye lot or batch number, printed on the label — can carry a faint shade difference from the next. Side by side on a wall, two lots of the same pattern can read as two slightly different colors. This is the reason the calculator rounds up and adds a margin.
Buy it all in one go
Order every roll the project needs in a single purchase, and check that the batch numbers match when it arrives. If you run short later and reorder, the new rolls may come from a different lot that no longer blends with what is already on the wall. A whole job can hinge on one missing strip.
Wallpaper definitions
How accurate is this wallpaper calculator?
The area math is exact. Perimeter times height, minus the openings you enter, is the precise wall area to the square foot. If your measurements are right, the geometry is right.
The roll count is a close estimate, by design. Real rolls vary a little in length, real pattern waste depends on where the repeat falls against your exact ceiling height, and a room with many corners, soffits or angled walls trims more than a plain rectangle. The waste bands here — 10% to 28% by match type, plus a 10% trim margin — match published install guidance, but treat the result as a confident order figure rather than a guarantee. Always confirm the roll length and pattern repeat printed on your specific paper, and order every roll in one dye lot, because running short is far more costly than a roll left over.
Frequently asked questions about the free Wallpaper calculator
About this wallpaper calculator
This wallpaper calculator runs entirely in your browser — nothing you enter is sent anywhere. It turns your room's wall area into whole rolls, applying the pattern-repeat waste and trim margin that a square-foot estimate leaves out, so you can order the right number of rolls in one dye lot.
It is one of the building and material estimators in our construction calculators collection, part of the wider library at calculator-s.cloud.