Nominal roll coverage under-orders
Shoppers divide wall area by the roll’s printed area and forget the pattern repeat, so the last wall comes up a roll short.
SHOPERIZE PRICE CALCULATOR
Shopify wallpaper calculator
Wall size in. Whole rolls out.
Wallpaper shoppers measure walls, not rolls, and pattern repeat makes the math harder than it looks. Shoperize Price Calculator takes wall width and height, adds your allowance, and adds whole rolls to the cart.
PRICE CALCULATORPREVIEW
Botanical Print Wallpaper28 sq ft per roll · 15% waste · rounds up to whole rolls- Area to cover
- 96 sq ft
- With 15% waste
- 110.4 sq ft
- Rolls to add to cart
- 4
- Purchased coverage
- 112 sq ft
THE MATH
A 12 × 8 ft wall, 28 sq ft usable per roll, 15% allowance
Use the usable coverage per roll after pattern matching, not the nominal roll area. Large repeats waste more of each roll, so they need a lower usable figure or a higher allowance.
| Step | Calculation | Result |
|---|---|---|
| Wall area | 12 × 8 | 96 sq ft |
| With 15% allowance | 96 × 1.15 | 110.4 sq ft |
| Rolls needed | 110.4 ÷ 28 | 3.94 |
| Rolls in cart | round up | 4 rolls |
| Coverage purchased | 4 × 28 | 112 sq ft |
WHY IT MATTERSWhere wallpaper orders
Where wallpaper orders
go wrong.
Each of these ends in a short order, a return or a support ticket.
Reorders don’t match
A second order can come from a different print batch, and the colour difference shows on the wall.
Rolls sold in pairs get split
If you sell double rolls, a free quantity box lets shoppers order an odd number you cannot ship.
SET IT UPLive on your product page
Live on your product page
without code.
Width × height calculators are included on the Free plan (one published calculator, up to three products). Pro adds quantity increments, separate limits for each dimension and collection assignment.
- Choose the Width × height recipe and label the inputs “Wall width” and “Wall height”.
- Enter the usable coverage of one roll for that pattern.
- Set the allowance for pattern matching and trimming.
- On Pro, set a quantity increment of 2 if you sell rolls in pairs.
- Publish, add the app block to the product template, and test a wall that needs exactly whole rolls.
WALLPAPER CALCULATOR FAQGood questions.
Good questions.
Straight answers.
How many rolls of wallpaper does a wall need?
Multiply width by height, add an allowance for pattern repeat, divide by the usable coverage of one roll and round up. A 12 × 8 ft wall with 15% allowance and 28 sq ft usable rolls needs 4 rolls.
How does pattern repeat change the calculation?
A larger repeat means more of each roll is cut away to line up the pattern. Lower the usable coverage per roll or raise the allowance for that design.
Can shoppers add several walls?
Shoppers can add each wall to the cart separately, or you can use an Area calculator so they enter the total of all walls.
Can I make shoppers buy rolls in pairs?
Yes, on Pro. Set a quantity increment of 2 and the calculated quantity is rounded up to the next pair.