THE FIT GUIDE

Apple Watch band size & fit guide.

Start with your watch's band connector group, then check wrist fit. Ultra and larger regular Apple Watches can share band sizes. Cases and covers need an exact model and case-size match.

01 / YOUR WATCH

Find your model.

Look at the back of your watch for the case size. Use Apple's identification guide to confirm the exact model and generation.

Identify your watch ›

02 / THE ACCESSORY

Choose your connector group.

Use the band-size groups below to understand interchangeable sizes. For a case or cover, match your exact watch model and case size instead.

03 / YOUR WRIST

Measure for comfort.

Measure around your wrist with a flexible tape. Compare that measurement with the band's stated fit range.

Ultra bands can fit regular Apple Watches.

For band connectors, 49 mm Ultra and 44 / 45 / 46 mm watches share compatible sizes. That works both ways. A band described as an Ultra style is not automatically Ultra-only.

Smaller connector group: 38 / 40 / 41 mm, plus the 42 mm Series 10
Larger connector group: 44 / 45 / 46 / 49 mm, plus the original 42 mm models through Series 3

The 42 mm exception

A 42 mm Series 10 uses the smaller band group. A 42 mm Series 3 or earlier uses the larger group. Check the generation as well as the number.

Apple recommends 44 / 45 / 46 mm bands on Ultra for casual everyday wear. A loop band's wrist fit can also change with Ultra's larger body. Check each accessory's listed fit.

Apple's band compatibility guidance › Series 10 band sizing ›

Cases and covers are different.

They fit around the watch body. Choose your exact generation and case size; shared band compatibility does not mean a case will fit.

Make the connection.

Follow the accessory's fitting instructions. Never force a connector. Check that both ends lock securely before wearing your watch.

Apple's band-changing guide ›

Apple Watch band sizing questions

How do I identify my Apple Watch model?

Open the Watch app on your iPhone and go to My Watch, General, then About. Tap Model Number to show the number beginning with A, then match it to Apple's model guide. Read the case size engraved on the back of the watch.

Where do I choose my watch size?

Use the Case Size selector on the product page. For a band, select the compatible connector group above. A 46 mm watch uses the larger group, even where the option lists 42 / 44 / 45 / 49 mm. For a 42 mm watch, check its generation first. For cases and covers, select the exact model and case size listed.

How do I measure my wrist for a band?

Wrap a flexible measuring tape around the part of your wrist where you wear your watch. Record the circumference and compare it with the selected band's wrist range. The watch's case size and a strap's end-to-end length are different measurements.

Can I choose a watch case using band compatibility?

No. A band attaches at the watch's connector slots, while a case or cover must match the watch body, screen and controls. Select a case made for your exact model and case size, even when a band can fit more than one model.

How do I attach an Apple Watch band?

Follow the accessory's instructions and Apple's band-changing guide. Use the watch's band-release button to remove the old band and slide the replacement into place. Never force it. Check that both ends lock before wearing the watch.