Window Flashing Tape Calculator
Estimate flashing tape for equal windows or doors from opening dimensions, taped sides, sill and head runs, corner/detail allowance, waste and roll length.
Default project preview
4 rolls
Tape per opening
22 ft
Base tape length
264 ft
Purchased tape length
300 ft
Opening perimeter
18 ft
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Tape per opening = vertical runs × height + horizontal runs × width + detail pieces. Multiply by opening count, add allowance and round to full rolls.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Window Flashing Tape Calculator questions
Why are side and horizontal runs editable?+
Installation sequences vary by product and opening type. Enter the number of full-height and full-width pieces shown in the selected detail.
Does this include a formed sill pan?+
Only if its tape length is represented by the horizontal and detail inputs. Prefabricated pans are separate products.
Can flashing tape be installed over any surface?+
No. Substrate condition, primer, temperature and compatibility must follow the tape and window instructions.