The lug width is the internal width between the lugs of watch, where watch strap fits with the watch

* Lug size differs from watch to watch ,which could be in a range of 16 to 26 mm , however the most common lug width is 20 mm for men and women these days. 

(A) If already own a strap, then the size of the lug will be mentioned at the back of strap like 19,20,22 or 24 mm, if not mentioned then follow option B and C to find the lug size.

(B) Or use a metric ruler or calliper to measure the distance between the inside of the lugs in millimetres (mm)

• (C) Or Guide chart (need to take print out of this and place your watch on sizes to find lug size of your watch.