Add walls in hanging order, choose the pattern match and see the exact number of rolls, drops and a practical cutting plan.
Wall order matters. The calculation starts at the left edge of the first wall and continues from left to right through the walls in list order. If a drop crosses a corner, its remaining width is shown at the start of the next wall.
Copy the exact width and length from the wallpaper label. UK rolls are commonly 52–53 cm wide and 10.05 m long, but sizes vary.
Useful for avoiding a very narrow final drop at the last corner.
Wallpaper required for the wall sizes, roll dimensions and pattern match entered above.
Orange sections are trimmed off to align the pattern; the grey end is the unused roll remainder. Drop numbers match those in the wall plan.
Check the product label before cutting. The true pattern start, uneven walls and the method used at corners may require extra allowance. Decorators often split wallpaper at internal corners and start the next wall from a new plumb line; the plan shows material use, not a mandatory hanging technique.
This calculator goes beyond wall area: it builds the actual sequence of drops and checks how each cut fits into the rolls.
Copy the roll width and length from the product label. The default UK roll is only a starting example.
Select free, straight or drop match. For patterned paper, enter the repeat and offset printed on the label.
Enter the width and height of every wall and arrange them in the order you intend to work around the room.
Use the wall plan to check drop positions and the roll plan to review cuts, matching waste and usable remainders.
Wallpaper is sold by the roll but hung as full-height vertical drops. A 25 m² wall area does not therefore mean that exactly 25 m² of paper is enough: each roll must yield enough full drops, and the remainder may be too short to use.
The calculator first lays drops across the combined wall widths. If one drop crosses a corner between walls of different heights, it uses the taller required cut so the material does not come up short.
The pattern repeat is the vertical distance before the same part of a design appears again. With a straight match, adjacent drops begin at the same pattern height.
A drop match may be shown as 64/32 cm: the design repeats every 64 cm and the next drop is offset by 32 cm. Enter the values printed by the manufacturer.
Top and bottom trimming allowances are added to every drop. The calculator then finds the next point on the roll where the required pattern phase begins; material before that point is shown as pattern-matching waste.
If the alignment gap and the next drop no longer fit in the open roll, the drop starts from a new roll. A small change to the repeat can therefore change the roll count.
Openings are not deducted directly because matching fragments are still needed above doors and above or below windows, and offcuts cannot always be reused elsewhere.
This gives a safer purchasing estimate. For unusually large openings, review the cutting plan with an experienced decorator before ordering.
Free, straight and drop matching and trimming allowances follow common wallpaper manufacturer guidance. Always follow the symbols and dimensions on your own product label.
Roll sizes, drops, pattern repeat, trimming allowance and spare material explained.