THE NUMBERS, EXPLAINED
How to use this calculator.
Waste is added before rounding up to complete packs. This is an area estimate, not a cutting layout.
Start with your inputs
Enter floor area (m²), pack coverage (m²), waste (%). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Floor area (m²) | 20 |
| Pack coverage (m²) | 2 |
| Waste (%) | 10 |
A worked example
With the example inputs above, whole packs is 11. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Whole packs | 11 |
| Purchased area (m²) | 22 |
How this is calculated
Whole packs
roundUp(a × (1+c ÷ 100) ÷ b)
Purchased area (m²)
roundUp(a × (1+c ÷ 100) ÷ b) × b
Symbols and units
- a
- Floor area (m²)
- b
- Pack coverage (m²)
- c
- Waste (%)
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
roundUp(x) rounds up to the next whole number. Values within two floating-point rounding units of an integer are treated as that integer.
Assumptions and limits
Waste is added before rounding up to complete packs. This is an area estimate, not a cutting layout.
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?
Whole packs; Purchased area (m²). 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: Waste is added before rounding up to complete packs. This is an area estimate, not a cutting layout.
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 →