THE NUMBERS, EXPLAINED
How to use this calculator.
Full drops are rounded up; pattern repeat rounds the drop length up to a repeat. Openings are not subtracted in this conservative strip model.
Start with your inputs
Enter wall run (m), wall height (m), roll width (m), roll length (m), pattern repeat (m). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Wall run (m) | 10 |
| Wall height (m) | 2.5 |
| Roll width (m) | 0.5 |
| Roll length (m) | 10 |
| Pattern repeat (m) | 0 |
A worked example
With the example inputs above, rolls is 5. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Rolls | 5 |
How this is calculated
Rolls
wallpaperRolls(a,b,c,d,e)
Symbols and units
- a
- Wall run (m)
- b
- Wall height (m)
- c
- Roll width (m)
- d
- Roll length (m)
- e
- Pattern repeat (m)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Calculation steps and notation
Round wall height up to a whole pattern repeat if a repeat is supplied. Strips needed = roundUp(wall run / roll width). Strips per roll = roundDown(roll length / adjusted drop). Rolls = roundUp(strips needed / strips per roll). Reject a roll too short for one drop.
Assumptions and limits
Full drops are rounded up; pattern repeat rounds the drop length up to a repeat. Openings are not subtracted in this conservative strip model.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Rolls. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Full drops are rounded up; pattern repeat rounds the drop length up to a repeat. Openings are not subtracted in this conservative strip model.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
Read the quality report →