Finding the right watch strap starts with understanding your watch size. Whether you’re swapping a worn-out band or upgrading to a new style, knowing your watch lug width, watch band width, and correct strap length ensures a proper fit and a balanced look. This watch size guide explains how to measure your watch correctly, answers common sizing questions, and helps you choose the perfect strap with confidence.
How to Know Your Watch Size
When people ask how to know your watch size, they’re usually referring to two key measurements:
- Watch lug width (strap width)
- Watch strap length (based on wrist size)
Both are essential. Even if the strap width is correct, the wrong length can make a watch uncomfortable or awkward to wear.
What Is Lug Width on a Watch?
Lug width on a watch is the distance between the inner edges of the lugs where the strap attaches to the watch case. This measurement determines the correct watch band lug width needed for a secure and seamless fit. You’ll always want your watch strap width to match your watch’s lug width.
Lug width is measured in millimeters, with the most common sizes being 20mm and 22mm. However, smaller, larger, and even odd sizes are common as well.
Choosing the correct watch band width ensures the strap fits snugly between the lugs without gaps or forcing.
How Do You Measure Lug Width on a Watch?
If you’re wondering how to measure the lug width on a watch, follow these 3 steps:
How to Measure Watch Lug Width
- Find a ruler or caliper tool that measures in millimeters.
- Measure the distance between the inside edges of the lugs and or your current watch strap at the watch end.
- Round to the nearest millimeter.
This measurement is your watch band lug width and strap size.
Some watchbands stamp the size on the underside. In this case, just refer to that number! If you see two numbers separated by a slash, take the larger number as the smaller one refers to the buckle width which can be different when a strap tapers.
If you see “18mm” – your watchband size is 18mm.
If you see “18/16” – your watchband size is also 18mm. The 16 refers to the buckle width.
Additionally, some watch manufacturers list lug width in the specifications on their website, so it’s worth having a look online as well to double check.
Watch Lug Width Chart
Use this watch lug width chart as a quick reference when shopping for straps:
| Lug Width or Strap Measurement | Strap Size | Commonly Found On |
|---|---|---|
| 17mm or 17/14 | 17mm | Vintage watches, less common |
| 18mm or 18/16 | 18mm | Vintage watches, smaller case sizes |
| 19mm or 19/16 | 19mm | Vintage chronographs, dress watches |
| 20mm or 20/18 | 20mm | Most modern midsize watches |
| 21mm or 21/20 | 21mm | Modern sport watches |
| 22mm or 22/20 | 22mm | Modern larger watches |
| 23mm or 23/22 | 23mm | Larger sport watches, less common |
| 24mm or 24/22 | 24mm | Heavy duty and extra-large watches |
A 20mm watch band is the most popular size but always confirm your own measurement before ordering.
Lug Width vs Lug-to-Lug: What’s the Difference?
Many people confuse lug width with watch lug-to-lug measurement.
- Lug width: width between the lugs, determining the strap size
- Lug-to-lug length: Lug-to-lug is the distance from the top lug to the bottom lug of a watch case. It measures how tall the watch is from end to end, and whether it might overhang on your wrist.
While lug-to-lug width affects how a watch wears on the wrist, it does not determine strap size. Strap sizing is based strictly on watch band width or lug width, not lug-to-lug length.
Watch Strap Length: How to Measure Wrist Size
Strap length is just as important as width. If you’ve ever wondered how to measure wrist size or how to measure your watch band size, follow the steps below:
How to Measure Wrist Size
- Wrap a flexible measuring tape (or string) snugly around your wrist.
- Note the measurement in inches. If you used a string, measure it with a ruler.
- Use this measurement to select the correct strap length.
Common Watch Strap Lengths
- Short: ~6″–6.5″ wrists
- Standard: ~6.5″–7.25″ wrists
- Long: ~7.25″+ wrists
At StrapsCo, many straps are offered in multiple lengths to ensure a comfortable fit without excess tail or tightness.
Putting It All Together: Choosing the Right Strap
To choose the correct replacement strap, confirm:
- Your watch lug width or your watch band width
- Your wrist size for proper strap length
For example:
- You measure your watch’s lug width at 21mm and your wrist at 7.1 inches. You would therefore need a 21mm standard length strap.
- You see 22/18 stamped on the underside of your current watchband. You measure your wrist at 7.5 inches. In this case, you’d want to get a 22mm long length strap.
Final Thoughts
Knowing how to measure your watch strap and wrist size removes all the guesswork from strap shopping. By understanding what is lug width on a watch, how to measure it accurately, and how to choose the right strap length, you’ll ensure a perfect fit every time.
If you’re ever unsure, StrapsCo’s detailed product listings and sizing information make finding the right strap easy, so you can focus on style, comfort, and enjoying your watch.
And don’t hesitate to contact us if you ever need help choosing a strap. We are always happy to assist and provide recommendations!
