Apple Watch Series 10 (46mm) vs Apple Watch Series 12 (46mm): Size & Dimensions

The Apple Watch Series 10 (46mm) and Apple Watch Series 12 (46mm) are most easily told apart by their overall size. They match almost exactly in height, at 46.0 mm. On width, the Apple Watch Series 12 (46mm) measures 40.0 mm against the Apple Watch Series 10 (46mm)'s 39.0 mm — about 1.0 mm more. They match almost exactly in thickness, at 9.7 mm.

The Apple Watch Series 12 (46mm) is the heavier of the two at 39.5 g, compared with 36.4 g for the Apple Watch Series 10 (46mm). That is a 3.1000000000000014 g difference (9%). The gap is small enough that you would barely notice it day to day.