Zipper Length Helper

Find the right zipper length and type for any garment or project.

Measure the seam opening the zipper will close

Standard Zipper Lengths for Common Garments

Garment / ProjectTypical OpeningRecommended ZipperZipper Type
Dress (back)18–22"20–22"Invisible or dress
Skirt (back or side)7–9"9"Invisible or dress
Pants fly6–8"7–9"Trouser/jeans
Jeans fly5–7"7"Jeans/metal teeth
Pillow (18")12–14"14"All-purpose or invisible
Tote bag10–14"12–14"All-purpose
Jacket / Hoodie20–28"Measure + 1"Separating
Cosmetic bag7–10"9–10"All-purpose or nylon coil

Zipper Type Guide

TypeWhen to UseNotes
Invisible / ConcealedDresses, skirts, blouses — hidden seam lookRequires an invisible zipper foot. Opens to one side of seam.
All-purpose / DressGeneral garments, home dec, pillowsMost common type. Comes in many colors and lengths.
SeparatingJackets, hoodies, cardigans, vestsSplits fully apart at bottom. Must match garment length exactly.
Trouser / JeansPants, jeans, shorts with fly frontShort, sturdy. Metal or nylon teeth. 7" or 9" common.
Exposed / DecorativeFashion garments, bags, sportswearZipper and tape are visible as a design element.
WaterproofOutdoor gear, rain jackets, swim bagsSealed teeth. Do not sew through tape — use clips or special feet.

How to Use the Zipper Length Helper

  • Measure the seam opening where the zipper will be inserted — from the top stop point to the bottom stop point.
  • Select your project type from the dropdown.
  • Click Find Zipper Length to see the recommended standard zipper size plus the next size up and down.

Key Rule: Always Round Up

  • Zippers come in standard lengths. Always buy the next size up from your opening length — you can shorten a zipper, but you cannot lengthen one.
  • For invisible zippers: buy at least 1" longer than your opening.
  • For separating zippers on jackets: measure the exact finished garment front opening and match it precisely.

Shortening a Zipper

  • To shorten a zipper, sew a new bar tack (hand or machine) at the desired length, then trim the excess tape below the new stop.
  • For all-purpose zippers: cut from the bottom. For separating zippers: only shorten from the top.

About this Zipper Length Helper

Use this free Zipper Length Helper to get quick, accurate results directly in your browser. It is designed for everyday use with no signup, no downloads, and no account required. No signup is required, and the tool works on phones, tablets, and desktop browsers.