Zipper Length Calculator
Calculate the correct zipper length for your garment opening. Accounts for zipper type (regular, invisible, separating) and seam allowances.
Inputs
Results
Buy This Length
7 in
How to Use This Calculator
- Enter the zipper opening length (inches) -- measure the gap in the seam.
- Set seam allowance (inches) and select zipper type (regular, lapped, invisible, or centered).
- Review recommended zipper length, minimum zipper length, seam opening, and tape extension.
- Standard zippers come in 2-inch increments -- round up to the next standard length.
- For invisible zippers, purchase a zipper 1-2 inches longer than the opening to allow for the pull stop.
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