• Design

All three devices look decent and stylish in their respective ways. However, we have a Forerunner 645 with a smaller case size compared to the other two which are quite bulky. The 645 is also a bit slimmer than the 945 and 935 and has a smaller 20mm straps size as compared to 22mm on the 935 and 945 which clearly suggests that the Forerunner 645 as a great choice for women while the 945 and 935 will suit men better.

The stainless steel bezel of the 645 also gives it the classic appearance that makes it a nice fit for official outings, but the finely crafted bezel of the 945 with the stylish markings is quite more commanding and outstanding.

As per durability, the 945 and 645 both have Corning Gorilla glass manning the screens which are more durable than the undisclosed chemical-strengthened glass of the 935 which means the 645 and 945 can well do with some knocks and still work fine (Better choices for adventure).

• Connectivity

The Forerunner 645 and 945 joins the list of Garmin’s smartwatches with NFC that supports Garmin Pay – a contactless payment system that allows you to make payment on the go from these two. Unlike the 935 which doesn’t have NFC.

• Fitness Tracking

As per fitness tracking, these three remain some of the best choices for fitness tracking. Each is packed with all the standard sensors you’d find in other high-end fitness smartwatches.

However, the new 945 comes with a Pulse Ox sensor that will be able to monitor blood oxygen level which is very insightful during acclimation activity helping you see how your body is adjusting to higher levels.

The Forerunner 945 also features the Garmin Coach which provides guidance and free adaptable training plans that suit your training style. You can as well create your own custom workout modes.

Also lacking on the 645 and 935, but available on the 945 is the full-color topography map feature that’s also available on the Fenix 5X Plus. The full-color map helps you navigate your way through even difficult terrains.

• Media

While the Forerunner 645 and 945 allow you to store your music on the watch which you can enjoy on the go, the 935 lacks that feature. Moreover, the Forerunner 945 has a higher onboard storage than the 645 as it can take up to 1000 tracks as against 500 on the 645.

• Battery Life

Each of these three has a remarkable battery life that lasts long enough to see you through a couple of days. However, the 935 and 945 have slightly longer battery life than the 645.

While you get about 10 days on regular usage with 935 or 945, you will get less than that with the 645, about 6 days which is still impressive.