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Wallpaper calculator

Drops = wall width ÷ roll width, rounded up. Each drop = wall height + trim, rounded up to whole pattern repeats. Rolls = drops ÷ (roll length ÷ drop length, rounded down). A standard roll is 53 cm × 10.05 m.

Your job

Walls

Use the highest point if the ceiling isn't level. Don't take off doors and windows.

Roll and pattern

The standard roll is 53 cm × 10.05 m. Check the label: some are 61.5 cm wide, and others vary, so enter your roll's width.

Pattern match

Look

Optional

The greyed number is an example only and is never used in your result.

4.00 m · 8 drops3.60 m · 7 drops5 rolls, 3 drops of 2.65 m from each

Every drop with the pattern at its true repeat. Below, the drops cut from each roll; hatched is offcut.

Rolls to buy

5rolls

15 drops at 3 a roll

Drops

15

Across 7.60 m of wall at 53 cm wide

Each drop

2.65m

Rounded to whole 53 cm repeats

Drops per roll

3

From a 10.05 m roll

Wall area

18.2m²

Doors and windows left in, as the maker advises

The working, with your numbers

  1. 1. Drops4.00 ÷ 0.530 ↑ + 3.60 ÷ 0.530 ↑= 15
  2. 2. Each drop(2.40 + 2 × 0.050) ÷ 0.530 ↑ × 0.530= 2.650 m
  3. 3. Drops per roll10.05 ÷ 2.650 ↓= 3
  4. 4. Rolls15 ÷ 3 ↑= 5
Typed those measurements in by hand?MetreMate measures them straight off your PDF plans. Free to start.

The formula, in plain words

  1. 1Drops per wall = wall width ÷ roll width, rounded up. Add every wall. Leave doors and windows in: it gives the right excess.
  2. 2Each drop = wall height + 5 cm trim at top and bottom, rounded up to a whole number of pattern repeats. Half-drop papers lose about half a repeat more per drop.
  3. 3Drops per roll = roll length ÷ drop length, rounded down.
  4. 4Rolls = drops ÷ drops per roll, rounded up. Buy them all from one batch.

Worked example

Two walls, 4 m and 3.6 m wide, 2.4 m high, in standard 53 cm × 10.05 m rolls with a 53 cm straight-match repeat.

  1. 1.Drops: 4 ÷ 0.53 = 7.5, so 8; 3.6 ÷ 0.53 = 6.8, so 7. 15 drops.
  2. 2.Each drop: 2.4 + 0.1 trim = 2.5 m, rounded up to 5 repeats of 0.53 = 2.65 m.
  3. 3.Drops per roll: 10.05 ÷ 2.65 = 3.8, so 3. Rolls: 15 ÷ 3 = 5.

Answer: 5 rolls (15 drops of 2.65 m).

How to measure it

  • Measure the width of each wall to be papered.
  • Measure the height at its highest point.
  • Read the roll width, length and pattern repeat off the label, and whether it's a straight or half-drop match.
  • Leave doors and windows in the measurement.

Where the numbers come from

Every default in the calculator is a number a supplier or manufacturer publishes. We list the source next to it so you can check.

WhatValueSource
Standard 'Euro roll': 10.05 m long and 0.53 m wide10.05 m × 0.53 mmeinewand, How do I calculate the number of rolls of wallpaper needed? (checked 2026-10-01)
Round each drop up to whole pattern repeats: 2.65 m at a 0.72 m repeat is 4 × 0.72 = 2.88 m; 10.05 ÷ 2.88 = 3 drops a roll0.72 m repeat (example)meinewand, Calculating wallpaper with a pattern repeat (checked 2026-10-01)
Half-drop papers offset every other drop by half a repeat0.5 × repeatBoråstapeter, Wallpaper calculator (checked 2026-10-01)
Leave approximately 5 to 7 cm for trimming at the top and bottom of each strip50 mm top and bottomSian Zeng, Traditional Hanging Guide (checked 2026-10-01)
Don't take off doors and windows: leaving them in gives just the right amount of excess0 deductedGraham & Brown (AU), How to measure for wallpaper (checked 2026-10-01)

Manufacturers named here are the source of the number, not a recommendation. Confirm quantities with your supplier.

Frequently asked questions

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