Strap Sizing Guide
How to Measure Your Watch Lug Width: Three Simple Methods
The lug width is the gap between the two lugs of your watch case, and it determines the width of the strap you need. Watch straps are always sized in millimetres (most commonly 18mm, 20mm or 22mm). Here are three simple ways to measure yours.
Method 1: Use a Ruler
Hold a ruler up against the watch and measure the gap between the inside edges of the two lugs, as shown above. Make sure you're reading the millimetre scale. The watch in this example has a lug width of 20mm, so it will need a 20mm watch strap.
Method 2: Use Digital Callipers
If you have a set of digital callipers, this is the most accurate method of the three. Open the inside jaws of the callipers between the lugs and read the measurement directly from the digital display. This removes any guesswork and is particularly useful if your watch has a non-standard lug width.
Method 3: Use the WatchObsession Lug & Strap Measuring Tool
Our purpose-made lug and strap measuring tool is designed for exactly this job. Hold it against the watch case to read the lug width, or feed an existing strap through the allocated gap to measure its width. It's quick, accurate and avoids the awkwardness of holding a ruler against a curved case.
Found Your Size? Browse Straps in Your Width
Once you know your lug width, you're ready to choose your next strap. Browse our full range of premium watch straps — filter by width to see every option in your size, from leather and rubber to nylon and FKM.
Still unsure? If you're between sizes or your watch has unusual lugs (curved end-link, integrated bracelet, fitted strap), drop us a message with a photo, and we'll confirm what fits.