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QUANTITY WORKSHEET / 07

Wallpaper calculator

Calculate wallpaper rolls from full drops, wall heights, roll dimensions and straight-match pattern repeat, with a cut-length breakdown.

How to use this calculator
  1. Add wall width and height, including spans across doors and windows. Equal-height walls can share full-drop batches.
  2. Enter the dimensions of one physical roll. A commercial “double roll” is not necessarily two separate rolls.
  3. Check straight/no-match pattern repeat and combined top-and-bottom trim. The breakdown shows cut lengths and drops per roll; half-drop is not supported.
Material quantity calculator

Your measurements

Units

Example values are loaded. Replace them with your measurements and product details.

MATERIAL & ALLOWANCES

Straight-match or no-match patterns only. Half-drop, murals and mixed-height offcut optimization are excluded.

Count full drops before counting rolls

Wallpaper is not reliably estimated by dividing wall area by roll area. Each drop must span the wall height plus trimming, and a repeating straight-match pattern can increase the cut length. This calculator counts full drops across each wall, then computes how many fit in a roll.

Walls with the same resulting cut length can share a roll batch. Different cut lengths are calculated separately, without optimizing short offcuts across heights. Windows and doors are not deducted: whole drops are counted across the wall width.

Cut length = wall height + total trim With repeat > 0: cut length = round up(cut length / repeat) × repeat Drops = round up(wall width / roll width) × copies Drops per roll = round down(roll length / cut length) Adjusted drops per cut-length group = round up(drops × (1 + extra / 100)) Rolls = sum(round up(adjusted drops / drops per roll))

Understand the inputs

Roll width and length
Enter one physical usable roll, not an ambiguous commercial single-roll or double-roll label. Confirm dimensions on the product.
Pattern repeat
Vertical repeat for a straight-match design. Enter zero for no-match paper. Half-drop matches, murals and panels require a different model and are not supported.
Total trim per drop
Combined extra length at both ends of a drop. Do not enter the top margin and forget the bottom, or double a total already combined.
Extra full drops
An optional percentage converted to whole extra drops within each cut-length group. Even a small percentage can add a full roll near a boundary.

Example: one straight-match wall

A wall is 3 m wide and 2.4 m high. The roll is 0.5 m wide and 10 m long, the total trim is 0.1 m and the repeat is 0.3 m. The 2.5 m height-plus-trim rounds to a 2.7 m cut length. Six drops cover the width; three full drops fit in each roll. With no extra drops, the estimate is two rolls. Remaining lengths are not automatically reused for a wall of another height.

Common estimating mistakes

  • Dividing wall area by roll area and ignoring cut length.
  • Using the repeat as an additional length instead of rounding to a complete repeat.
  • Entering half-drop wallpaper in the straight-match model.
  • Treating a seller’s roll-count label as physical roll dimensions.

What this estimate leaves out

No half-drop matching, pattern-centering loss, reverse hanging, murals, mixed-height cutting optimization or damaged-length recovery is modeled. Check whether your product requires additional starting-pattern loss; it is not automatically included. Stock counts full usable rolls only. Match product, color and batch explicitly.

Product information & references

Manufacturer estimators account for roll dimensions and repeat. Check the match type and product instructions before using this model.