The Apple Watch started life in two simple sizes, but there are now three separate models covering four different case sizes.
And that’s not including the models that are not currently officially on sale.
While the band of any Apple Watch is changeable and adjustable, the size of the case itself is crucial to get right before purchasing.
Here’s the breakdown of each Apple Watch’s case sizes:
- Apple Watch Series 10 – 42/46mm
- Apple Watch Series 9 – 41/45mm
- Apple Watch Series 8 – 41/45mm
- Apple Watch Series 7 – 41/45mm
- Apple Watch Series 6 – 40/44mm
- Apple Watch SE 2 – 40/44mm
- Apple Watch Ultra/Ultra 2 – 49mm
The new 46mm watch impressed with its big display for easy-to-read text. But it will be far too big for some people. It’s important to remember that the smallest size has also increased and is a viable option for a lot of people, not just those with the smallest wrists.
If you’re wondering which size Apple Watch you should get, we’ll show you how to measure your wrist and find the right fit. Discover the full dimensions, weights, and important details of band compatibility in this guide.
Apple Watch sizes explained

- Apple Watch SE (and Series 4, 5, 6): 40mm and 44mm (left)
- Apple Watch Series 9/8/7: 41mm and 45mm (middle)
- Apple Watch Series 10: 42/46mm
- Apple Watch Ultra/Ultra 2: 49mm (right)
The size of the Apple Watch has grown steadily over the years and now comes in 42mm and 46mm option. That means the smallest Series 10 is now the size of the biggest original Apple Watch. Madness.
The Apple Watch Series 9 retains the 41mm and 45mm case sizes introduced through the Series 7 in 2021, which means older bands will still be compatible with the latest smartwatch.
And what’s more, 40mm and 44mm bands are still compatible with the new, larger size.
The Apple Watch Series 4, Series 5, and Series 6 models come in 40mm and 44mm – as does the Apple Watch SE (2020) and SE (2022).
You can no longer buy the Series 3 or lower, which used 38mm and 42mm case sizes.
These measurements, we should make clear, denote the size of the bezel, though the straps do always play a role in the specific fit of the smartwatch on your wrist.
Full list of Apple Watch case sizes and weights
Here’s the information in table format:
Model | Dimensions (mm) | Weight (GPS) | Weight (GPS + Cellular) | Weight (Titanium) |
---|---|---|---|---|
Apple Watch SE (40mm) | 40 x 34 x 10.7 | 26.4g | 27.8g | N/A |
Apple Watch SE (44mm) | 44 x 38 x 10.7 | 32.9g | 33.0g | N/A |
Apple Watch Ultra 2 (49mm) | 49 x 44 x 14.4 | 61.4g | N/A | N/A |
Apple Watch Series 10 (42mm) | 42 x 36 x 9.7 | 30.0g | 29.3g | 34.4g |
Apple Watch Series 10 (46mm) | 46 x 39 x 9.7 | 36.4g | 35.3g | 41.7g |
Apple Watch strap sizes explained

If you’re wondering which size band to purchase for your Apple Watch, listen up.
Bands sizes for 38 mm, 40 mm, and 41 mm Apple Watch cases are interchangeable.
In addition, Apple Watch straps for 42 mm, 44 mm, 45 mm, and 46 mm case sizes also all work together.
That means, for the first time, that Apple Watch Series 10 small and large options use the same strap size.
Finally, 44 mm, 45 mm, and 46 mm straps will all work with the 49mm Apple Watch Ultra.
Sizing Solo Loop bands
Also keep in mind that, with some, you’ll have to choose a size when buying, and others (like the Sport bands) come with both an S/M and M/L strap for you to pick between.
The Apple Solo Loop bands have a heap of sizes, for example, and Apple has a tool to measure your wrist so you pick the right size. That’s crucial — and take it from our experience, you don’t want to get this wrong. We’d recommend getting a proper tape measure to do it, too. If it’s slightly slack, getting accurate health data will be a nightmare.
How to measure your wrist

The fit of your watch is a fairly subjective thing, but it’s important to know just how big your wrist is before buying the Apple Watch or an additional band.
So, how can you tell for sure? Well, get out the flexible tape measure and size up that wrist.
Hold the strip just below where your wrist bone sits and around where you would normally wear the band, wrap it around your wrist, and line that up with the sizes of your Watch model.
Generally speaking, a small wrist is 5 – 6.5 inches and a large wrist is between 7 – 8.5 inches, but the good thing about many Apple Watch bands is that you can adjust with velcro or within the perforations of sports straps to find a very specific fit.
Just don’t go too tight or too loose – not only can it become uncomfortable, but it also affects the accuracy of the Apple Watch’s heart rate monitor.