Will My Old Apple Watch Bands Fit the New 42mm and 46mm Sizes?

Short answer: almost certainly, yes. Bands made for 38mm, 40mm and 41mm Apple Watches fit the new 42mm size. Bands made for 44mm, 45mm and 49mm watches fit the new 46mm size. There is exactly one trap to avoid: a band from an original 42mm Apple Watch (Series 1 to 3) fits the new 46mm, not the new 42mm. Everything else carries straight over.

When Apple moved to 42mm and 46mm cases with the Series 10, and kept them for the Series 11, plenty of long-time Apple Watch owners looked at a drawer full of straps and wondered if they had all just become expensive bracelets. They have not. Here is exactly how the sizing works, why it works, and the one situation where an old band will not fit.

The Two Band Families

Since the very first Apple Watch in 2015, Apple has used the same slide-and-lock connector on every model. The band slides into a channel on the case and clicks into place. That connector has never changed, which is why bands remain interchangeable across generations.

What has changed over the years is the case size, and every case belongs to one of two band families:

The small family: 38mm, 40mm, 41mm and the new 42mm. Any band made for any of these sizes fits all of them.

The large family: the original 42mm (Series 1 to 3 only), 44mm, 45mm, 49mm (Ultra and Ultra 2) and the new 46mm. Any band made for any of these sizes fits all of them.

The Cheat Sheet

It works in the other direction too. Any band sold for the new 42mm fits older 38mm, 40mm and 41mm watches, and any band sold for the new 46mm fits older 44mm, 45mm and 49mm watches.

The One Trap: Old 42mm vs New 42mm

This is the bit that catches people out, and it is worth reading twice if your strap collection goes back a while.

On the original Apple Watch, Series 1 through Series 3, 42mm was the large size. On the Series 10 and Series 11, 42mm is the small size. Same number on the box, completely different band family.

So if you have a band that was bought for a Series 1, 2 or 3 in 42mm, it will fit the new 46mm watch perfectly. It will not fit the new 42mm watch. If you try to match old 42mm to new 42mm purely on the number, you will end up with a band that is too wide for the case.

Will a Smaller Band Look Odd on a Bigger Case?

Functionally, no, and cosmetically, barely. Because the new 42mm case is slightly wider than the old 38mm case, a 38mm-era band can look a touch narrow where it meets the lugs. The lock is just as secure and the watch is just as safe on your wrist. Most people never notice. If the look bothers you, a band sized for 40mm or 41mm sits almost flush on the new 42mm case.

The same logic applies at the big end: a 44mm-era band on a 46mm case sits fractionally narrower at the lugs but locks in exactly the same way.

What About Ultra Bands?

Bands made for the Apple Watch Ultra and Ultra 2 (49mm) share the large-family connector, so they fit the new 46mm case. They are built for a chunkier watch, so some styles can look slightly oversized on the slimmer case, but the fit is secure. The reverse is also true: 44mm, 45mm and 46mm bands fit the Ultra.

Buying a New Band for a 42mm or 46mm Watch

Every Apple Watch band at OzStraps uses the standard Apple connector, so the entire range carries over to the new sizes, whether you are after silicone, nylon, leather or stainless steel. When you are shopping, simply pick the size option that matches your watch. If your watch is the new 42mm, shop the 42mm (Series 10, 11) collection or choose the small size on any product page. If your watch is the new 46mm, shop the 46mm (Series 10, 11) collection or choose the large size.

New to swapping bands? Our guide on how to change your smartwatch band covers the Apple Watch slide-and-lock system step by step.

Browse the full range at https://ozstraps.com.au/collections/apple-watch, with free shipping on orders over $30, same-day dispatch on orders placed before 1pm, and a 12-month warranty on every band.

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