The fastest way is to flip over your existing strap and look for a number printed or stamped on the back. A number like 22 means your watch takes a 22mm strap - that's all you need to know.

Most smartwatches will show 18, 20, or 22 on the back of the strap or on the underside of the watch itself. The number refers to the strap width - how wide the strap is where it attaches to the watch - not the overall length of the strap.

The lug width is the distance between the two metal prongs (lugs) on one end of your watch case - this is exactly where the strap attaches, and it's the same as the strap width you need to order.

Your watch has four lugs - two at the top and two at the bottom. Measure between the two lugs on either end (the red line in the diagram above). Both ends will give the same measurement.

• Lay your watch face-up on a flat surface.
• Place a ruler or tape measure across the top set of lugs.
• Measure the gap between the inner edges of the two lugs.
• That number (in mm) is your strap size.

Both measuring methods in the image above give 22mm - so this watch takes a 22mm strap.

If you're still unsure, you can also measure the top of your existing strap where it meets the watch (marked A in the diagram below). Don't measure further down - straps taper as they get longer, so you'll get a smaller number than you need.

For popular watch brands and models, you can often find the lug width with a quick Google search. This works well if you know your exact model name or number - manufacturers sometimes change strap sizes between models, so the more specific you can be, the better.

Search for:

For example:

If the lug width search returns nothing, try replacing "lug width" with strap width - both terms are used interchangeably.

View common smartwatch strap sizes →