Wallpaper Calculator

Calculate Wallpaper

m

Sum of all walls to be papered

m
m
cm
cm

Set to 0 for plain wallpaper

Wall Area

37.5 m²

Strips

29

Rolls Needed

8

Add 1 extra for safety

How This Calculation Works

The wallpaper calculator works by dividing the total wall length by the roll width to determine how many vertical strips you need. It then calculates how many strips fit on a single roll by dividing the roll length by the wall height (plus any pattern repeat allowance).

If the wallpaper has a pattern repeat, each strip must be shifted to align the pattern. This means some material is wasted at the top or bottom of each strip. The calculator adds the repeat length to each strip's height to account for this.

Standard European rolls are 10 m long × 53 cm wide. American rolls vary — double rolls are common. Always check the roll dimensions printed on the label.

Common Mistakes to Avoid

  • Ignoring pattern repeat. A 30 cm pattern repeat can waste 20–30% of each roll. This is the biggest source of error in wallpaper calculations.
  • Confusing single and double rolls. Many wallpapers are priced per single roll but packaged as double rolls. Confirm what "one roll" means before ordering.
  • Not ordering from the same batch. Colours vary between print batches. Order all your rolls at once and verify the batch numbers match.
  • Skipping an extra roll. Hanging errors, miscuts, and future repairs all require spare material. Always buy one extra roll beyond the calculated amount.

Worked Example

Scenario: A room with a total wall perimeter of 14 m, 2.5 m high walls, using standard 10 m × 53 cm rolls with a 25 cm pattern repeat.

Step 1 — Strips: 14 ÷ 0.53 = 27 strips (rounded up from 26.4).

Step 2 — Strip length: 2.5 + 0.25 = 2.75 m per strip (including repeat).

Step 3 — Strips per roll: 10 ÷ 2.75 = 3 strips per roll (rounded down).

Step 4 — Rolls: 27 ÷ 3 = 9 rolls. Buy 10 rolls (one extra for safety).

Frequently Asked Questions

What is a pattern repeat and why does it matter?
A pattern repeat is the vertical distance before the design repeats itself. When hanging, each strip must be offset so the patterns align across strips. This wastes material — the larger the repeat, the more waste. Plain or textured wallpapers have no repeat.
How do I measure for wallpaper around windows and doors?
Measure the full wall as if no openings exist, then subtract half a roll per standard window and one strip per door. This conservative approach accounts for the pieces needed above and below openings.
Can I hang wallpaper over old wallpaper?
It is generally not recommended. Old wallpaper may peel, bubble, or show texture through the new layer. For best results, remove old wallpaper and apply to a clean, primed surface.
How many rolls should I buy as extras?
Buy one extra roll per room. This covers mistakes, miscuts, and future repairs. If the wallpaper is discontinued later, you'll be glad you have spares.