How the calculation works
The formulas
Use a known perimeter or sum wall segments. Deduct only openings where skirting will not be installed. Purchased pieces round up from total adjusted length; individual cuts are not optimized.
Net length = perimeter or Σsegments − Σexcluded widths × count
Required length = net length × (1 + waste/100)
Stock pieces = ceil(required length ÷ stock length)
Assumptions to check
- Mitres, joint positions, defects, and offcut reuse need a separate cutting check.
- Surplus stock may not yield usable lengths for every segment.
A worked example
An 18 m perimeter minus 2 m of openings leaves 16 m. With 10% waste and 2.4 m stock, buy 8 pieces (19.2 m).