Apple Watch Band Size Guide: Which Size Do You Need?

Found an Apple Watch band you love but not sure which size to pick? You're not alone — Apple's sizing looks more confusing than it actually is, and the good news is you only ever have to choose between two options. This quick guide shows you exactly how to find your size in about ten seconds, so your new Apple Watch band fits perfectly the first time.

The 10-second version: check the back of your watch

Every Apple Watch has its case size engraved right on the back, near the band connectors. Slip your current band off and look — you'll see a number like 40mm, 45mm, or 49mm. That number is all you need. Match it to the table below and you're done.

Which size should you choose?

All of our bands come in two size options. Here's exactly which one to pick based on your watch:

Your watch case size	Choose this option
38mm, 40mm, 41mm, or 42mm (Series 10–11)	38 / 40 / 41 / 42mm (Series 10–11)
42mm (Series 1–3), 44mm, 45mm, 46mm, or 49mm	42mm (Series 1–3) / 44 / 45 / 46 / 49mm

The only slightly tricky one is 42mm, because it appears on two very different watches. If you have a newer Series 10 or 11, pick the first option. If you have an original Series 1, 2, or 3, pick the second. When in doubt, the back of your watch settles it — and if it still isn't clear, just reach out and we'll help you figure it out.

What if I don't know my series?

No problem — you don't actually need to know it. The engraved case size on the back is enough to choose. But if you're curious or the engraving is worn, you can check on the watch itself: open the Settings app on your Apple Watch, tap General, then About, and scroll to Model. You can also find it in the Apple Watch app on your paired iPhone under General → About.

Will the band fit my wrist?

The case size (the two options above) is about matching the watch, not your wrist. Our bands are designed to be adjustable to fit a comfortable range of wrist sizes, so once you've picked the right case size, the fit around your wrist is covered. If you have an especially small or large wrist and want to double-check, message us before you order and we'll walk you through it.

Ready to find your match?

Now that sizing is sorted, the fun part: picking your vibe. Whether you're after something edgy and studded, soft and floral, or bright and playful, every band swaps in seconds — so you can change your whole look without changing your watch.