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CONSTRUCTION CALCULATOR

Wallpaper Calculator

Count full-height wallpaper drops for one width, a rectangular room or separate wall widths. Include straight-match repeat, trim, roll starting loss and spare rolls.

Calculator

m
m
m
m
cm
cm
Enter 0 for plain paper. Half-drop and offset patterns are not modeled.
m
m
One wall width per row. All walls use the entered height.
Advanced options
cm
USD
Currency labels your price; it does not convert it.
YOUR RESULTS
Rolls required3
Full-height drops needed
8
Drops per roll
3
Planned length per drop
2.56 m
Total roll length purchased
30 m
Purchased length above planned drops
9.52 m
Rolls needed before spares
3
Wallpaper roll cost
90.00 USD

All walls use one height and straight-match repeat. Separate walls each round to full drops. Starting loss is reserved per used roll; spare rolls remain unopened. Check your supplier’s physical package dimensions.

Full drops per wall
Full drops per wall
WallWidthFull drops
14 m8
Page guide

Planned drops, roll count, and unused length

Drops per roll round down; purchase rolls round up and include your unopened spares. Unused length excludes the entered alignment loss on used rolls, while retaining uncut drops and spare-roll length. The wall table shows where full-drop rounding adds strips.

For walls that will be painted instead, the Paint Calculator uses coated area and the product’s coverage.

The formula

Drop = height + total trim, rounded up to a full repeat when repeat > 0. Drops = sum ceil(each wall width ÷ roll width). Usable drops per roll = floor((roll length − starting loss) ÷ drop). Needed rolls = ceil(drops ÷ usable drops); purchase = needed rolls + spares.

Separate walls each round upward so a partial-width strip is not assumed reusable around a corner. All walls use one height, repeat and product. One starting loss is reserved per used roll; unopened spare rolls are added after the cutting estimate.

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

  1. Choose one continuous width, a rectangular room or separate wall widths. Enter the common wall height. Unit changes convert wall and roll measurements.
  2. Enter actual roll width and length, total trim per drop and the straight-match repeat. Each separate wall rounds its drop count upward.
  3. Set starting alignment loss, optional spare rolls and roll price under Advanced options. Review drops per roll, the wall breakdown and purchase cost.

Openings and uneven walls

The estimate keeps full-height drops across doors and windows. Reusing offcuts depends on their position and pattern.

A room creates four separately rounded walls. The wall list also rounds every wall separately rather than transferring a partial-width strip around a corner. Walls of different heights still need separate estimates.

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, murals, defects, complex corners and mixed wall heights.
  • Entered alignment loss is a planning allowance, not an automatic pattern-position calculation.

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.

Does a roll label mean one or two physical rolls?

Enter the width, total usable length and price of the package you will buy. Retail single-roll and double-roll naming differs; this calculator counts packages with your entered dimensions.

Sources & further reading

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