Garmin Forerunner 45 Review

A runner wears the Garmin Forerunner 245 GPS watch

Garmin designed the brand new Forerunner 45 to replace the aging Forerunner 35—and the update is exactly what the running watch needed.

The Garmin Forerunner 35 is a classic, no-fuss GPS running watch, and the 45 doesn’t mess with that basic setup. The new timepiece is lightweight, easy to use and comfortable to wear. It’s the ideal watch for runners who want GPS tracking without a confusing interface or cumbersome hardware. And it only costs $200.

Garmin also makes the new 45 in two sizes: small and large. The small comes with a slightly smaller face and shorter strap, while the larger bumps up the face dimensions and fits larger wrists. But the hardware, software and functions are all identical.

The refresh comes as part of an overhaul of Garmin's Forerunner series. The watchmaker dropped the Garmin Forerunner 245—an update to the Garmin Forerunner 235—and the Garmin Forerunner 945 to replace the Forerunner 935. The new watches add improved software and safety features to an already impressive lineup.

We tested the Garmin Forerunner 45 in a large size to see how it worked in real-life use, how accurate it was and how it compares to the outgoing 35. Here’s what we thought of Garmin’s newest smartwatch.

The Garmin Forerunner 45 in Black, showing GPS running data

Garmin Forerunner 45 Hardware, Sensors and Battery Life

Like other Garmin running watches, the Forerunner 45 uses chemically strengthened glass to cover its digital face. But unlike some more expensive Garmin devices, like the Garmin Forerunner 645 Music, the 45 rims the glass in a durable plastic bezel instead of metal.

The display size for both the small and large sizes is 1.04 inches (26.3 mm) in diameter, and it packs 208 x 208 pixels across the screen.


  • Size: 39.5 x 39.5 x 11.4 mm
  • Fits wrist circumference of 124-185 mm
  • Weight: 32g


  • Size: 42 x 42 x 11.4 mm
  • Fits wrist circumference of 129-197 mm
  • Weight: 36g

The most noticeable change from the outgoing Forerunner 35 is the 45’s shape. The previous model employed a square-shaped face; the new version is round, like Garmin’s other watches.

The Forerunner 45 uses a similar silicone strap to Garmin’s more expensive models, with one exception: The straps on the Forerunner 645 and the new Forerunner 245 come with a quick release design that lets you swap different colored bands without using any tools, but the straps on the 45 are screwed onto the body. Garmin sells other colors of bands, but they won’t snap in and out like the Quick Release versions.

While you can’t easily swap out bands, the silicone band is soft and flexible, which makes it comfortable to wear for workouts, dinner dates or just lounging on the couch. The whole thing only weighs 36 grams, so you barely feel it on your wrist.

“It’s so light and low-profile that I don’t even think about it,” our tester says. “Some other watches tend to get caught up when I’m putting on a jacket or button down shirt, but I never had that problem with the 45.”

Garmin says the battery in the Forerunner 45 will last up to a week in smartwatch mode and track 13 hours in GPS mode. Our tester says the battery life was long enough to get him through a week of running without needing a charge. When it did eventually need some juice, it charged quickly. The watch soaked up a full charge in about an hour and a half when it was plugged into a computer.

Garmin didn’t use the same charging clip as on other watches and products, though. The 45 comes with a USB cable that plugs into the back of the watch.

Also on the back of the watch, a heart rate sensor keeps tabs on your pulse. The wrist-based optical heart rate monitor uses LED lights to illuminate how quickly blood flow through veins and capillaries. That data is then used to estimate a person’s heart rate.

The monitor on the Forerunner 45 accurately recorded our testers heart rate. He happened to have a yearly physical while testing the watch, and his resting heart rate estimate from the watch matched the measurement taken by the nurse. But even with the accurate resting heart rate, Garmin includes an important note about heart rate measurement for its watches: There are inherent limitations to the technology, and it’s not meant to be used for medical purposes.

But what most runners want from a running watch is accurate GPS tracking. To that end, the 45 taps into GPS, GLONASS and Galileo satellite systems to you can keep track of your runs no matter where you go. The watch found a satellite signal quickly and was just as accurate as other Garmin watches we’ve tested before, giving our tester the same distance he expected from his normal routes.

A comparison of the Garmin Forerunner 35 and the Garmin Forerunner 45
The Garmin Forerunner 45 GPS watch in Lava Red, showing heart rate data

Garmin Forerunner 45 Features and Software

Despite its $200 price tag, the Forerunner comes packed with a suite of software and features that make it feel like a much pricier model. We found it did everything a beginning runner would want from a GPS watch, and it might even satisfy some advanced runners looking for a simple training device.

The 45 tracks all the basic metrics we want: distance, pace and overall time. Throw in heart rate for an idea of how hard a workout is and a timer, stopwatch and alarm clock, and it’s got the only things we really need to run better. But, like a second scoop of ice cream, it never hurts to have a little more.

Garmin made the 45 smarter by including activity (or lack-of-activity) tracking. The watch counts your steps all day long and sets goals for you based on your previous days’ activity; there’s also a move bar that keeps tabs on your inactivity—sit for too long, and it’ll remind you to get up and get moving.

It also provides an estimate of VO2 max—the amount of oxygen your body can use during intense exercise—and a number called “Body Battery” that estimates your energy reserves based on your heart rate, stress and activity that day. A higher number means you have more fuel left in the tank, while a lower number means you’re running on fumes.

Along with a guess at the calories you burn and sleep monitoring, the Forerunner 45 has plenty of stats to keep you busy. Our tester says the numbers (and intuitive interface with Garmin’s compatible app, Garmin Connect) are fun to dive into, but ultimately it’s the watch’s basic functions that make the 45 a great value.

“I’m not an ultramarathoner or triathlete, so I don’t really need anything more than the 45 has,” he says. “It has enough data to keep me busy if I want to read into it, but it also just shows me how far and how fast I run, which is enough for me.”

To check all the data, the watch pairs easily with a cell phone for automatic syncing via Bluetooth. You can watch real-time stats, like heart rate and steps, in the Garmin Connect app while you’re wearing the watch.

Once it’s paired with your phone, you can choose to get notifications on your wrist. Texts and calls show up on the watch face, and you can answer a call by pushing a button on the watch (although you can’t talk through the watch—you still need your phone for that). But never fear, you can also turn notifications off if you don’t want your watch blowing up during group texts.


The Garmin Forerunner 35 was a sleek and capable running watch for years. But the Forerunner 45 is even better.

Garmin updated the entry-level 45 with a refreshed round face and a new bag of tricks that includes customizable watch faces and personalized training plans from Garmin Coach. The improvements make the 45 an ideal GPS running watch for new runners, runners on a budget or experienced runners who only want to track their distance, pace and time.

Still not convinced? Don’t sweat it. Fleet Feet's return policy means you can test drive your shoes and gear without risk. If you’re not happy with the way your gear performs, looks or fits, we’ll take it back within 60 days. Plus, you’ll get free return shipping on all orders. That's our Happy Fit Guarantee.

By Evan Matsumoto. Evan played many sports growing up but didn’t go pro in any of them. Now, he’s the digital copywriter for and editor for the Fleet Feet blog where he writes about different foam densities and engineered mesh uppers.

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