Free Online Calculators
Calculate rolls including pattern repeat
This wallpaper calculator tells you exactly how many rolls you need for your room, including the pattern repeat and one reserve roll. Enter room length, width and height, the number of doors and windows, the roll format and the pattern repeat; the calculator adds 10 cm to every drop and handles the maths for you. No more guessing at the DIY store.
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One of the most common mistakes when decorating a room is ordering the wrong amount of wallpaper. Buy too little and you risk running out mid-project; buy too much and you waste money. Our free Wallpaper Calculator takes the guesswork out of the equation by calculating the precise number of rolls you need – including the all-important pattern repeat.
The calculator uses the dimensions of your room and the specifications of your chosen wallpaper to determine exactly how many rolls are required. It deducts a fixed width from the wall perimeter for every door and window, and crucially, it accounts for any pattern repeat that adds to material waste.
The result shows the perimeter to be papered, the number of drops, the drop length (room height plus 10 cm, rounded up to whole pattern repeats), the drops per roll, the exact number of rolls and the rolls plus one reserve roll.
The pattern repeat is one of the most overlooked factors when calculating wallpaper. It refers to the vertical distance after which a design repeats on the roll. When hanging patterned wallpaper, each strip must be aligned so that the pattern continues seamlessly from one strip to the next. This means cutting off a portion of each strip before hanging it, resulting in significant waste if the repeat is large.
For example, at a room height of 2.40 m the calculator cuts each drop 2.50 m long, so a 10.05 m Euro roll gives 4 drops. With a 64 cm pattern repeat each drop becomes 2.56 m (four repeats) and only 3 drops fit on a roll. For a 4 m × 3.5 m room with one door and one small window that means 9 instead of 7 rolls – a crucial detail our calculator handles automatically. At 2.50 m room height the same repeat changes nothing in this room: drops of 2.60 m and 3.20 m both give 3 per roll.
Imagine you’re wallpapering a bedroom that measures 4 m × 3.5 m with a room height of 2.40 m. There are two small windows and one door. You choose a Euro roll (10.05 × 0.53 m) with a pattern repeat of 32 cm.
The calculator computes the perimeter: (4 + 3.5) × 2 = 15 m, minus 0.90 m for the door and 2 × 0.80 m for the windows, leaves 12.50 m. That makes 24 drops. With the 32 cm repeat each drop is 2.56 m long, so a roll gives 3 drops: 8 rolls, 9 with the reserve roll. Without a pattern repeat the drops would be 2.50 m, 4 per roll, and 7 rolls including the reserve would do.
Professional decorators and interior designers always stress the importance of accounting for pattern repeat. Underestimating your wallpaper needs can be costly because wallpapers are produced in batches. Different batches – even from the same design – can have subtle colour variations. If you run out and reorder, the new batch may not match perfectly. This is why the calculator always adds one reserve roll to its result; for large rooms or big pattern repeats a second one can be worth it.
Getting the right number of rolls is just the first step. Always check that all rolls share the same batch number (printed on the label) to ensure colour consistency. Even rolls from the same collection can differ slightly between batches.
Measure the ceiling height in several spots around the room, especially in older buildings where floors and ceilings may not be perfectly level. Use the highest measurement as your reference to ensure no strip comes up short. It's also worth noting that textured or embossed wallpapers may behave differently from printed patterns, so always check the manufacturer's guidance.
For a standard room of about 12–15 m² with a room height of 2.40–2.50 m, one door, one small window and no pattern repeat, the calculator gives 7 to 10 Euro rolls (53 cm wide) including the reserve roll. However, this varies significantly depending on room shape, openings, and pattern repeat. Use the calculator for an accurate figure.
Simply enter 0 for the pattern repeat. Plain, solid-colour, or textured wallpapers without a defined repeat don't require any extra material for alignment. The calculator then cuts each drop at room height plus 10 cm.
The pattern repeat is printed on the wallpaper label, usually shown as a number in centimetres alongside a symbol featuring two offset arrows. It can range from 0 cm (no repeat) to 64 cm or more for large floral or geometric patterns.
Yes, absolutely. The standard recommendation is to order 10–15% more than the calculated amount. This covers cutting errors, damaged strips, and future touch-up repairs. The calculator shows the exact number of rolls and the rolls plus one reserve roll.
Yes. Choose “Fleece roll (10.05 × 1.06 m)” as the roll format. You then need about half as many drops: for a 4 m × 3.5 m room 2.50 m high with one door and one small window, 13 drops, 5 rolls, 6 with the reserve roll. Wide-format wallpapers often result in fewer joins, which can improve the overall finish.