Apple Watch bands: which size fits my watch?

The two band groups

Apple’s UK Store puts it like this: “38mm, 40mm, 41mm and 42mm straps are compatible with 38mm, 40mm, 41mm and 42mm case sizes. 44mm, 45mm, 46mm and 49mm straps are compatible with 44mm, 45mm, 46mm and 49mm case sizes.”

Why 42mm is confusing

Apple’s support article says “Straps for 42mm, 44mm and 45mm cases are compatible with each other”. That puts 42mm in the larger group. The Store’s compatibility note, which also covers today’s 42mm case, puts 42mm in the smaller group. Neither page says which 42mm watch it means. The original Apple Watch models had 38mm and 42mm cases, where 42mm was the bigger one. Series 10 and later come in 42mm and 46mm, where 42mm is the smaller one.

We follow the Apple Store, so on this site Series 10 and later 42mm watches take smaller-group bands. If you have an older 42mm watch, check with the band maker before buying.

Ultra

Ocean Band, Alpine Loop and Trail Loop are 49mm bands designed for Ultra. Apple says Ultra also fits 44mm, 45mm and 46mm bands, but these “should only be worn for casual, everyday use”.

Before you buy

• Check your case size on your watch’s device page. Pick your watch in the bands filter and only matching bands show.
• Solo Loop and Braided Solo Loop come in fixed sizes and only fit Apple Watch SE, Series 4 or later and Ultra.
• Some Apple bands note that they contain magnets “and may cause interference with Compass on Apple Watch”.
• Third-party bands state their own compatibility. We list the case sizes each maker gives.