Apple Watch 38 / 40 / 41 / 42 mm (smaller)

Apple Watch accessories — smaller case

The smaller Apple Watch case is the choice for people who prefer a compact watch on a slimmer wrist. Straps are interchangeable across the whole 38-42 mm group thanks to an identical attachment system, while cases and glass must match the specific case size.

Strap compatibility

• 38 mm — Series 1, 2, 3
• 40 mm — Series 4, 5, 6, SE (1st gen.)
• 41 mm — Series 7, 8, 9, SE (2nd gen.)
• 42 mm — Series 10

A strap labelled "38/40/41/42 mm" fits each of the models above.

Accessory types

• Silicone straps — sporty, comfortable, available in many colours
• Nylon and braided straps — light, breathable, with Velcro adjustment
• Metal bracelets — mesh, link, magnetic clasp
• Protective cases (bumper) — protect the watch case from scratches and impacts
• Tempered glass and films — matched to the screen size

What to look out for

When choosing a case or glass, what matters is the exact case size — 40 mm and 41 mm are different body dimensions. A universal 38-42 mm strap will work with every model, but a 40 mm case does not fit a 41 mm watch. You can check the size of your watch on the back of the case or in the Watch app on your iPhone.

Looking for a larger size? See Apple Watch 42-49 mm. Accessories for Ultra: Apple Watch Ultra.

FAQ

Does an Apple Watch 40 mm strap fit the 41 mm?

Yes — straps in the smaller case group (38/40/41/42 mm) are compatible with each other. You can keep using the same strap after upgrading to a newer generation.

How do I check my Apple Watch case size?

The size is engraved on the back of the watch case. You can also check it in the Watch app on your iPhone, under General > About.