Lug Width
Lug width is the gap between the lugs, in millimetres, where the strap fits. It is usually an even number such as 18, 20 or 22mm, and it tells you which straps will fit your watch. Knowing the right figure makes buying a replacement strap easy. It is not the same as lug-to-lug, which is the overall case length.
At a glance
- Unit
- Millimetres (mm)
- Common values
- 18, 20, 22mm (even numbers)
- What it tells you
- Which straps will fit
This is the one figure to know before you buy a strap. It measures the gap between the inner edges of the lugs in millimetres, and once you have the right number, you will never order the wrong band again.
Why it is an even number
Lug width is almost always an even number, because the strap market is standardised around these sizes.
- Common sizes: 18, 20 and 22mm are the ones you will come across most often
- The fit rule: for fitted spring-bar straps, match the lug width as closely as you can; a strap wider than the gap will not fit at all, and one that is too narrow leaves a gap or side-play and looks wrong, though pass-through (NATO) straps tolerate a 1mm difference
That is why, when you hunt for a replacement strap, you look at the lug gap rather than the case diameter.
Do not confuse it with lug-to-lug
Lug width is the horizontal gap, whereas lug-to-lug is the overall vertical length of the case and decides how the watch sits on the wrist. The two are read for different jobs, much like case diameter. For more, see the Size and Fit category and our guide to the best watches for beginners.
Examples
For a first watch, a common lug width such as 22mm makes life easy, since replacement straps in that size are everywhere.
View this watchTo find the lug width, simply measure the gap between the inner edges of the lugs with a ruler.
View this watch
Comparison
Lug width and lug-to-lug are often confused, but they measure different things.
| Option A | Option B | Notes |
|---|---|---|
| Lug width | Lug-to-lug | Lug width is the horizontal gap between the lugs and sets strap fit; lug-to-lug is the overall vertical length of the case. |
Related terms
Watches that show this
Frequently asked questions
How do I measure my watch's lug width?
Measure the gap between the inner edges of the lugs, where the strap sits, in millimetres. A ruler is enough. The result is almost always an even number such as 18, 20 or 22mm.
Is lug width the same as lug-to-lug?
No. Lug width is the gap between the lugs and tells you which strap fits. Lug-to-lug is the overall length of the case and decides how the watch sits on your wrist. The two are measured for different purposes.
Why is lug width an even number?
Because the strap market is standardised around even sizes. That is why lug width is usually an even number such as 18, 20 or 22mm, which makes finding a replacement strap straightforward.