Understanding your result
The planned drop length includes top-and-bottom trim and repeat alignment. Drops per roll round down; rolls to buy round up. Unused length includes the remainder in opened rolls and any unused planned drops.
For walls that will be painted instead, the Paint Calculator uses coated area and the product’s coverage.
The formula
A roll cannot provide a fraction of a full-height drop. A patterned paper may therefore yield fewer usable drops than a plain paper with the same roll area. Repeat rounding assumes all planned drops start at a matching point.
Worked example
For a 4 m wide, 2.4 m high wall, use eight 0.53 m drops. With 10 cm total trim and a 64 cm straight repeat, plan 2.56 m per drop. A 10 m roll yields three drops, so the estimate is three rolls.
How to use this calculator
- Measure the width being covered and the tallest wall height.
- Copy the physical roll dimensions, not a single-roll-equivalent label.
- Enter total trim and the straight pattern repeat printed on the product.
Openings and uneven walls
This estimate keeps full drops across doors and windows rather than subtracting their areas. Some offcuts can be reused, but that depends on placement and pattern alignment. Combining widths assumes equal wall heights and reusable width at corners; calculate walls separately if corners or different heights create additional waste.
Match type and roll starting point
Straight-match patterns align at the same height across adjacent strips. Half-drop, offset, alternating A/B rolls, and murals need their own cutting plan and are outside this model. A roll may also need an initial cut to find the matching pattern position. Inspect the product and allow for that starting loss before relying on a tight order.
Assumptions & limitations
What this calculation assumes
- Plain or straight-match paper; every roll starts at the planned pattern alignment.
What to keep in mind
- Excludes offset matches, initial alignment loss, defects, and complex corners.
Common questions
Why can two similar wall heights need different roll counts?
Crossing a repeat boundary lengthens every planned drop, which can reduce the number fitting on each roll.
Do I subtract doors and windows?
Usually keep the full width for this conservative full-drop estimate. A detailed cutting plan can identify reusable offcuts separately.