Journal · Published 18 October 2026
How to measure your watch’s lug width
It is the one measurement you need to choose a strap, and it takes two minutes without taking the watch apart.

What is lug width?
The lugs are the two arms of the case that hold the strap’s spring bar. Lug width is the inside gap between them, in millimetres. It is also the width of your strap where it attaches.
Method 1: a ruler
Lay the watch flat, dial up. Hold a ruler marked in millimetres against the case and read the gap between the inside edges of the lugs. Round to the nearest whole millimetre.
Method 2: calipers
More precise, calipers tell a 19 from a 20 mm. Slide the jaws between the lugs without forcing and read the value. The most common widths run from 18 to 22 mm.
Method 3: the spec sheet
Many brands list lug width in the watch’s specifications. You will also find the widths we have recorded for over 400 models on our pages by brand and by width.
What about the buckle width?
A strap often tapers towards the buckle: 20 mm at the lugs and 18 mm at the buckle, for example. To reuse your original buckle, measure the inside of its frame and enter it in the bespoke configurator.
Pitfalls to avoid
Don’t measure your old strap, which may have stretched. Watch out for specific fittings (Cartier Santos, Tissot PRX) and integrated straps (Royal Oak, Nautilus): they need a bespoke strap. If in doubt, see our size guide.




