Free · Home and garden calculators 🏡

Wallpaper Area, Rolls and Pattern Allowance

Estimate wallpaper rolls using wall or room area, openings, repeat-height allowance and quoted roll price.

  • Formula & worked example
  • Private in your browser
  • No signup
Go to tool

Calculator inputs

Loading calculator…

How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A 4 m by 3 m room with 2.5 m walls has 35 m² of wall area before openings. With 0.5 m pattern repeat, 10 m by 0.5 m rolls and no openings, this area model needs seven rolls; at 10 each the budget is 70.

Adjusted height = ceil(height/repeat) × repeat; net allowance area = (gross−openings) × adjusted/height; rolls = ceil(area/(roll width×length)).

Worked example

Enter these known values and leave the other values blank.

Room length
4 m
Room width
3 m
Room height
2.5 m
Number of doors
0
Number of windows
0
Roll length
10 m
Roll width
.5 m
Pattern repeat
.5 m
Cost per roll
10 USD
Room surface area
35 m²
Total doors area
0 m²
Total windows area
0 m²
Adjusted height
2.5 m
Adjusted room area
35 m²
Number of rolls
7
Total cost
70 USD

Assumptions and limitations

  • The allowance is an area method that rounds wall height up to a whole pattern repeat; it does not simulate each drop or reserve edge trimming. Actual matching and reusable offcuts can change the purchase count.
  • Subtract only openings that materially save paper. Room mode assumes four rectangular walls; single-wall mode uses width and height.
  • Clear an unknown before solving backward. Currency controls represent the chosen denomination without exchange rates; prices must use the selected denominator units.
  • Whole package, board, roll or truss ceilings use exact decimal arithmetic. An amount just above a whole-number boundary needs the next whole unit; numeric display rounding does not lower the purchase count.

Common questions

What is included in this estimate?

The allowance is an area method that rounds wall height up to a whole pattern repeat; it does not simulate each drop or reserve edge trimming. Actual matching and reusable offcuts can change the purchase count.

References

Enforce the documented geometric domains and positive whole counts. Integer membership is checked with isInteger, so ordinary, tiny and large fractional counts are rejected even when tolerant floor equality would pass. Use exact decimal ceilings for whole material quantities; the captured mathjs ceiling snaps sufficiently near integers and can undercount immediately above a boundary.

Explore home and garden calculators 🏡 or browse all construction calculators.