Free Online Calculators
Calculate rolls including pattern repeat
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 factors in window and door areas that don't need to be covered, and crucially, it accounts for any pattern repeat that adds to material waste.
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, with a pattern repeat of 64 cm and a ceiling height of 2.50 m, each strip requires roughly 3.14 m of wallpaper to allow for alignment. From a 10-metre roll, you can only cut 3 complete strips instead of the 4 you might expect. This represents a 25% increase in material needed – a crucial detail our calculator handles automatically.
Imagine you're wallpapering a bedroom that measures 4 m × 3.5 m with a ceiling height of 2.40 m. There are two windows (1.2 m² each) and one door (2 m²). The wallpaper has a roll width of 53 cm, a roll length of 10 m, and a pattern repeat of 32 cm.
The calculator computes the total perimeter: (4 + 3.5) × 2 = 15 linear metres. It determines the number of strips, applies the waste factor from the pattern repeat, deducts the window and door areas, and divides the total length by the roll length. The result might be 9 rolls – already including a recommended safety buffer.
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 building in a buffer of at least 10% is standard practice, and our calculator does this for you.
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 ceiling height of 2.40–2.50 m and no large pattern repeat, you typically need 8 to 12 rolls of standard-width wallpaper (53 cm). 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 will then compute based purely on the wall area and roll dimensions.
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. Our calculator already includes this buffer in its results.
Yes. Simply enter the correct roll width (106 cm) in the appropriate field. The calculator adjusts the number of strips per roll and the total roll count accordingly. Wide-format wallpapers often result in fewer joins, which can improve the overall finish.