Window Opening Flashing Strip Cut Order calculator.
Order continuous sill, jamb and head tape strips from supplied opening measurements and detail extensions.
Your inputs
Use measurements from your plan and properties from your chosen product. Any prefilled values are illustrative.
A clear estimate starts here.
Enter your dimensions and product details to see the quantity and purchase breakdown.
Formula and assumptions
How this calculation works.
Order continuous sill, jamb and head tape strips from supplied opening measurements and detail extensions. Each opening has sill width + 2 returns, two jamb heights + supplied extra, and head width + 2 extensions.
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Selected flashing roll length
- 10 m
- Specified sill strip extra at each end
- 0.2 m
- Specified extra per jamb strip
- 0.2 m
- Specified head extension at each end
- 0.2 m
- Measured opening width
- 1 m
- Measured opening height
- 2 m
- Identical openings
- 2
Flashing tape rolls for specified opening strips: 2 rolls
Continuous-piece packing uses decreasing-length first fit. It is feasible for the stated pieces but is not guaranteed optimal. No cut kerf, damage or end trim is assumed; include these in your supplied piece lengths. Strip order, corner details, tape width and compatibility must come from your existing specification.
Before you purchase
Use dimensions from your plan and properties from your chosen product. Any design spacing, section or fixing pattern must already be specified.
All product dimensions, coverage, density, allowances and joining rules must come from your supplied plan or selected product. No building-code values are inserted.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-05. Calculation and review policy.