Apple Watch Band Sizing Guide

Apple Watch Band Sizing Guide

Universal size combination	Compatible models	Case size
38mm丨40mm丨41mm丨42mm	Apple Watch	38mm
	Series 1
	Series 2
	Series 3
	Series 4	40mm
	Series 5
	Series 6
	SE
	Series 7	41mm
	Series 8
	Series 9
	SE2
	Series 10	42mm
42mm丨44mm丨45mm丨46mm	Apple Watch	42mm
	Series 1
	Series 2
	Series 3
	Series 4	44mm
	Series 5
	Series 6
	SE
	Series 7	45mm
	Series 8
	Series 9
	SE2
	Series 10	46mm
44mm丨45mm丨49mm	Ultra	49mm
	Ultra 2

Core Principles: Two Size Categories

Apple Watch strap compatibility can be simply divided into two series: " small size " and " large size ".

• Small size universal series (38mm / 40mm / 41mm)

  • If you have an Apple Watch with a 38mm, 40mm, or 41mm case, all bands listed in those three sizes are compatible with each other. For example, a band designed for a 41mm Series 9 will fit perfectly on an older 38mm Series 3.

• Large size universal series (42mm / 44mm / 45mm / 49mm)

  • Likewise, if you own a watch with a 42mm, 44mm, 45mm, or 49mm (Apple Watch Ultra) case, all bands listed in those sizes are also compatible. For example, an off-road band designed for an Apple Watch Ultra (49mm) will also work perfectly with a 44mm Apple Watch SE.

How do I determine my Apple Watch case size?

The quickest way to find out is to flip over to the back of your watch . Around the circle surrounding the heart rate sensor, you'll see engraved text that clearly indicates your case size, such as "41MM" or "45MM."

Apple Watch case sizes overview

Apple Watch offers a variety of case sizes. Here are the detailed sizes for the different series: