Wallpaper Calculator
Enter the room size, the roll size from the label and the pattern repeat. The wallpaper calculator gives the number of rolls and the cost at your price. For a feature wall, list just that wall and it counts the strips.
Wallpaper calculator
Quantities are estimates. Pattern matching and waste vary by design and installer.
Bare numbers are meters; 190 mm works too.
Bare numbers are meters; 190 mm works too.
Bare numbers are meters; 190 mm works too.
European standard: 0.53 m (21 in).
European standard: 10 m (33 ft).
The vertical pattern repeat on the roll. 0 means no repeat (straight match).
Your price, any currency. Leave blank to skip.
Assumptions
Change any value to match your product or local rules.
Basis: For trimming top and bottom and cutting mistakes; roll offcuts and the pattern repeat are already counted. Used for a whole room only: listed walls are counted in whole strips.
- Net wall area
- 39.03 m²
- 420.1 sq ft
- Openings subtracted
- 3.09 m²
- 33.3 sq ft
- Rolls needed
- 11
- Cost (your currency)
- Add a price to see the cost
11 rolls of wallpaper for 39.03 m², with 10% added.
How this was calculated
- Net wall area = wall area − openings
- Strip length = wall height, rounded up to a whole number of pattern repeats (no repeat: the wall height)
- Strips per roll = roll length ÷ strip length, rounded down
- Coverage per roll = strips per roll × roll width × wall height
- Rolls = net wall area × (1 + wastage) ÷ coverage per roll, rounded up
- Listed walls: strips = Σ (wall length ÷ roll width, rounded up) × count; rolls = strips ÷ strips per roll, rounded up
- Perimeter = 2 × (4.20 m + 3.60 m) = 15.60 m
- Gross wall area = 15.60 m × 2.70 m = 42.12 m²
- Opening 1 = 0.81 m × 2.03 m × 1 = 1.65 m²
- Opening 2 = 1.20 m × 1.20 m × 1 = 1.44 m²
- Net wall area = 42.12 m² − 3.09 m² = 39.03 m²
- Strip length = wall height 2.70 m = 2.70 m
- Strips per roll = 10.00 m ÷ 2.70 m, rounded down = 3 strips
- Coverage per roll = 3 × 0.53 m × 2.70 m = 4.29 m²
- Rolls = 39.03 m² × 1.1 ÷ 4.29 m², rounded up = 11 rolls
How it works
Enter the walls
Room width and length, or list each wall. For a room it works from the net wall area less doors and windows; for listed walls it counts whole strips.
Enter the roll size
Width and length from the label. The European standard is 0.53 m wide × 10 m long.
Set the pattern repeat
The vertical distance the pattern repeats. 0 means no repeat (straight match). Half-drop matches need extra length.
Read the rolls
Number of rolls with your wastage allowance, and the cost if you enter a price.
Worked example
A 4.2 × 3.6 m room with 2.7 m walls, one door and one window: net wall area = 39.03 m². A 10 m roll gives 3 whole strips of 2.7 m (the last 1.9 m is offcut), so each 0.53 m roll covers 3 × 0.53 × 2.7 = 4.29 m². With 10% added: 39.03 × 1.1 ÷ 4.29 is just over 10, so 11 rolls.
In feet: a 14 × 12 ft room with 9 ft walls, one 3 × 7 ft door and one 4 × 4 ft window: net area = 468 − 21 − 16 = 431 sq ft. A 33 ft roll gives 3 strips of 9 ft, so a 21 in roll covers 3 × 1.75 × 9 = 47.25 sq ft. With 10%: 474 ÷ 47.25 = 10.03, so 11 rolls.
Feature wall wallpaper calculator
For one wall or a few, choose "Only the walls I list below" (or the Feature wall example). The calculator then counts whole strips instead of dividing an area: each wall needs its length ÷ roll width strips, rounded up, and each roll gives as many full-height strips as fit in its length. Openings are not deducted and no wastage is added, because whole strips already include the trim.
A 1.55 m wide wall, 2.7 m high, with a 0.53 × 10 m roll: 1.55 ÷ 0.53 = 2.92, so 3 strips. One roll gives 3 strips of 2.7 m, so 1 roll is enough. Dividing the area instead (4.19 m² plus 10% over 4.29 m² per roll) would say 2. A 3.6 m wall needs 7 strips, so 3 rolls.
Pattern repeat and matching
The pattern repeat is the vertical distance before the pattern lines up. Straight matches line up every strip; half-drop matches stagger by half the repeat, which wastes more length. Free-match or random-match patterns have no repeat. Check the label on the roll for the repeat length.
Roll size
European wallpaper is typically 0.53 m (21 in) wide × 10 m (33 ft) long. US wallpaper is typically 0.52 m (20.5 in) wide × 10.05 m (33 ft) long. The calculator uses 0.53 m × 10 m as the default. Check your roll label.
Wastage allowance
The calculator already counts whole strips per roll and the pattern repeat, so the 10% default is for trimming at the ceiling and skirting and a spare strip for mistakes. A room with many doors and windows may need more. Patterned and textured wallpapers need more care when hanging, so allow a spare strip.
Frequently asked questions
How many rolls of wallpaper do I need?
Work out how many full-height strips one roll gives, then divide the net wall area (plus wastage) by the area those strips cover, rounding up. A 4.2 × 3.6 m room at 2.7 m high with a 0.53 × 10 m roll needs 11 rolls with 10% added.
How do I account for pattern repeat?
Type the repeat length from the label. A larger repeat means each strip needs more length, which means fewer strips per roll and more rolls overall.
What is a standard wallpaper roll size?
European standard: 0.53 m wide × 10 m long. US standard: 0.52 m wide × 10.05 m long. The calculator defaults to the European size.
Do I subtract doors and windows from the wallpaper area?
For a whole room, yes. Measure the frame size of each opening and subtract it from the gross wall area. The wallpaper stops at the reveal, same as paint. For listed walls the calculator counts full strips and does not deduct openings, since strips run above and below them.
What is pattern match?
Straight match lines up every strip at the same point. Half-drop matches stagger by half the repeat. Free-match or random-match has no repeat. The pattern repeat field rounds each strip up to whole repeats, as for a straight match; for a half-drop, entering the full repeat gives a safe estimate.
Ready to plan your space?
It is free, runs in your browser and needs no account. Projects are saved privately on this device.