What To Measure
1) Strap width (lug width)
Strap width is the distance between the inside edges of your watch lugs, measured in millimeters (mm). This number is the strap size you need (common sizes are 16–24mm).
2) Strap length (wrist fit)
Strap length depends on your wrist circumference and how your watch wears. Two-piece straps usually come in short/regular/long; NATO straps are typically sized by total length.
Optional: Taper & buckle
Many straps “taper” toward the buckle. You may see sizing like 20–16 (20mm at the lugs, 16mm at the buckle).
How To Measure Lug Width
Measure the inside gap between the lugs (not the outside), ideally with a mm ruler or calipers.
Method A: Check your old strap
- Look on the back/inside of the strap for a number like 18, 20, 22.
- If it fits your watch perfectly, order the same mm width.
Method B: Measure the watch lugs
- Place the watch on a soft cloth.
- Measure the gap between the inside of the lugs in mm.
- Round to the nearest whole mm (strap widths are typically whole numbers).
Common widths
Tip: If you measure a “half” size (like 19.5mm), re-check. Most straps come in whole mm widths, and measuring from the inside of the lugs is key.
Choose The Right Strap Length
Measure your wrist
- Wrap a soft tape (or string) where you wear the watch.
- Keep it snug, not tight, and note the measurement in mm.
- If using string, measure it against a ruler.
Wrist → strap length idea
A practical method is to estimate the needed strap length by subtracting your watch head length from your wrist circumference, then choosing a short/regular/long option that matches.
| Wrist circumference | Suggested strap length | Best for |
|---|---|---|
| 140–160 mm | Short | Smaller wrists / minimal tail |
| 160–190 mm | Regular | Most wrists |
| 190–210+ mm | Long | Larger wrists / more adjustment |
Fit preference matters: if you wear your watch loose or prefer the buckle centered, size up; if you want less strap tail, size down.
Common Questions
What does 20–16 mean?
It means the strap is 20mm wide at the lugs and tapers to 16mm at the buckle/clasp for a refined look and lighter feel.
Can I use a 21mm strap on a 20mm watch?
It’s not recommended. A strap that’s too wide can pinch, bend, or fail to fit between the lugs; too narrow leaves gaps and looks off.
Do NATO straps use the same width?
Yes—NATO width still matches lug width (e.g., 20mm NATO for a 20mm lug watch). Length is chosen separately depending on wrist size and hardware style.