Smartwatch case sizes by brand
Short answer: 145 of 311 models in our catalog list a case size. The listed sizes run from 36.5 mm to 52.8 mm, and the most common size is 46 mm. Size depends on the brand, so check the table before you look at features.
Last verified September 26, 2026.
How sizes are listed
Most makers give the case diameter in millimetres, and some list weight in grams. Where a maker sells several sizes of one model, we show all of them. Where no size is listed, we show "not listed" and leave that model out of the ranges.
Case size range by brand
| Brand | Models listing a size | Smallest (mm) | Largest (mm) | Most common (mm) | Models with weight listed |
|---|---|---|---|---|---|
| Amazfit | 22 | 42 | 51.4 | 47 | 1 |
| Apple | 9 | 40 | 49 | 42 | 0 |
| Fitbit | 2 | 40 | 40.5 | 40 | 0 |
| Garmin | 21 | 41 | 51 | 51 | 8 |
| Huawei | 18 | 41 | 48.5 | 46 | 0 |
| Polar | 8 | 43 | 48.6 | 47 | 1 |
| Samsung | 13 | 40 | 47 | 40 | 1 |
| Xiaomi | 11 | 39 | 47.6 | 46 | 1 |
Smallest and largest listed models
The ten smallest listed case sizes in the catalog. Models with no size listed are left out.
| Model | Brand | Size | Weight |
|---|---|---|---|
| Realme Watch (1st gen) | Realme | 36.5 mm | - |
| Withings ScanWatch Light | Withings | 37 mm | - |
| Withings ScanWatch 2 | Withings | 38 / 42 mm | - |
| POCO Watch | Xiaomi | 39 mm | - |
| Apple Watch SE (2nd gen) | Apple | 40 / 44 mm | - |
| Apple Watch SE 3 | Apple | 40 / 44 mm | - |
| Fitbit Versa 3 | Fitbit | 40 mm | - |
| Galaxy Watch 5 | Samsung | 40 / 44 mm | - |
| Galaxy Watch 6 | Samsung | 40 / 44 mm | - |
| Galaxy Watch 7 | Samsung | 40 / 44 mm | - |
The ten largest listed case sizes in the catalog. Models with no size listed are left out.
| Model | Brand | Size | Weight |
|---|---|---|---|
| TicWatch Atlas | Mobvoi | 52.8 mm | - |
| Amazfit T-Rex Dual Solar | Amazfit | 51.4 mm | 69 g |
| Garmin D2 Mach 2 Pro | Garmin | 51 mm | - |
| Garmin Enduro 2 | Garmin | 51 mm | - |
| Garmin Enduro 3 | Garmin | 51 mm | - |
| Garmin Fenix 8 Pro AMOLED | Garmin | 47 / 51 mm | - |
| Garmin Fenix 8 Pro MicroLED | Garmin | 51 mm | - |
| Garmin Fenix 9 | Garmin | 43 / 47 / 51 mm | - |
| Garmin Fenix 9 Pro | Garmin | 43 / 47 / 51 mm | - |
| Garmin Tactix 7 AMOLED | Garmin | 51 mm | - |
How to choose a size for your wrist
Measure your wrist first, see how to measure your wrist. A case wider than your wrist looks awkward and can tilt, and a very small case can be hard to read. Many makers offer two sizes, so read the strap range too. Weight matters if you sleep with the watch on or run with it.
Reading the ranges
A wide range inside one brand means it sells several sizes or both small and large lineups. A narrow range means most of its models share one case size. The most common size is a count of listed models, so it favours brands with many models. Do not read the common size as the best size: it only tells you what is most often listed.
Sizes and strap length
Case size and strap length are separate. A watch with a small case can still use a long strap, and many straps can be swapped. If your wrist is under about 15 cm or over about 19 cm, check the maker's strap range for your size before you choose the case.
When no size is listed
Some entries show "not listed". For those, check the maker's page, because the case may come in one size that we have not recorded.
Weight and comfort
Where a weight is listed, it is usually for the case without the strap. A light case on a heavy metal bracelet can feel different from the number in the table. If comfort matters for sleeping or sport, prefer a light case, a soft strap and the smaller size your wrist allows, and check the weight on the maker's page.
Before you buy
Confirm the exact size in the listing, the strap length and the weight. Sizes change between generations. Check the maker's current details. See display types explained and our methodology.