Check your watch size

Read the back of the watch

The case size in millimetres is engraved on the back of nearly every smartwatch. Apple Watch: 38–49 mm. Galaxy Watch: 40–47 mm. Garmin uses model names (Fenix 8 47 mm vs 51 mm).

Match the generation

Same size is not always the same shape: Apple Watch 45 mm (Series 7–9) and 46 mm (Series 10–11) differ, and Galaxy Watch 5 Pro is not Watch 5. Every Suoman listing names both the models it fits and the ones it doesn't.

Phone cameras

Lens covers are cut per phone: iPhone 18 Pro and 18 Pro Max have different camera bumps.