Seiko 5 20mm Strap: Complete Compatibility Guide

If you own a Seiko 5 and are looking to change its strap, the most frequently asked question in watch forums is always the same: what exact lug width does my model have?

The good news: the vast majority of Seiko 5 watches use a 20mm lug width. But not all of them do, and getting the size wrong is the number one mistake when buying a new strap.

The Shortcut Almost Nobody Knows About

Before grabbing a ruler, turn your current strap over and look at the inside, near the buckle. Many leather, silicone, or nylon straps have the width already engraved or stamped there (for example, a small "20"). If your strap has it, you'll save yourself the trouble of measuring anything. On the watch itself, however, it's almost never indicated — so don't waste time looking for it there.

How to Find Your Seiko 5's Lug Width Without Tools

  1. Look between the two lugs where the current strap is attached (remove it if you can, you'll see the gap better).
  2. Place a ruler right there, and measure from the inner face to the inner face of the lugs — from the inside edge of one lug to the inside edge of the other, not from outside to outside.
  3. Round to the nearest even number: 18, 20, 22, or 24mm.

Most classic Seiko 5 references (SNK, SNKL, SNKK) have 20mm. The more robust models in the range (some SRPD) may have 22mm.

Our Recommendation

At Vergio, we label each strap by exact width — currently 20 and 22mm, with more widths coming soon.

Do you have doubts about your specific model? Write to us and we'll help you identify it before you buy.