Skip to content
Lug Leather

Guides · Guides & Comparisons

How to Measure a Watch Strap

Two measurements, one minute, no special tools — get the lug width and length right the first time.

By Stephen V.Updated How we research
#ad

We earn a commission when you buy through our Amazon links, at no extra cost to you. It never affects our picks, and we say so when the cheaper watch is the better buy. How this works.

Buying a strap that fits comes down to two numbers: the lug width (so the strap fits between the lugs) and the length (so it fits your wrist). You can find both in about a minute with a ruler. Here is exactly how.

If you already know your watch model, you may not need to measure the width at all — our lug width chart lists it for dozens of popular watches. Otherwise, follow the steps below.

Step by step

Measure your watch strap in four steps

  1. 1

    Measure the lug width

    Remove the old strap or look at the gap between the lugs where the strap meets the case. Measure that gap in millimeters with a ruler or caliper. It is almost always an even number — 18, 20 or 22mm. This is the number that must match your new strap.

  2. 2

    Check the case diameter as a sanity check

    Measure the case width (excluding the crown) in millimeters. Lug width is usually about half the case diameter, so a 40mm watch is typically 20mm and a 44mm watch 22mm. If your lug measurement is far from this, measure the lugs again.

  3. 3

    Measure the strap length you need

    If you are replacing a whole strap, measure your current strap end to end (both halves, excluding the buckle) or wrap a tape measure around your wrist. Most straps are sold in a standard length that fits a 6.5-to-8-inch wrist; note if you have a smaller or larger wrist so you can choose a short or long option.

  4. 4

    Note the fitting type

    Check whether your watch takes standard spring bars or has quick-release bars (a small lever on the strap). Quick-release straps swap with no tools; standard bars need a spring-bar tool. NATO-style straps thread through under the caseback and fit any spring-bar watch of the right width.

What to do with your measurements

Once you have the lug width, ordering is simple: buy a strap in exactly that width. For material, match it to how you'll use the watch — leather to dress up, nylon for toughness and water, silicone for the pool. Our best watch straps guides rank the options in each. When your strap arrives, changing it takes a couple of minutes.

Questions

Frequently asked

How do you measure a watch strap size?
Measure the lug width — the gap between the lugs where the strap sits — in millimeters. It's almost always an even number (18, 20 or 22mm). For length, measure your existing strap end to end or wrap a tape around your wrist. The lug width is the number that must match your new strap exactly.
What tools do I need to measure a watch strap?
Just a ruler or a small caliper marked in millimeters. A caliper is more precise for the lug gap, but a ruler is fine for the standard even sizes. You don't need any special watch tools to measure — only to change the strap.
How do I know what length strap to buy?
Most straps come in a standard length that fits roughly a 6.5-to-8-inch wrist. If your wrist is smaller or larger than that, look for a 'short' or 'long' option, or measure your current strap end to end (excluding the buckle) and match it.

Keep reading

Related

Receipts

Sources

We do not run a testing lab, and we do not pretend to. Every spec above traces to a manufacturer listing or a named standard; where we could not verify something, we say so on the page rather than quietly leaving it out. Read our full method.