I biked 9 miles with the new Garmin Forerunner 165 to test GPS accuracy — and I’m impressed

Garmin Forerunner 165 on wrist looking at post workout stats.
I appreciate the post workout elevation report on the new Forerunner 165. (Image credit: Dan Bracaglia/Future)

There's a fresh fitness tracker in town: the Garmin Forerunner 165. In addition to hands-on time with this sporty, new wearable, I had the chance to put it through its paces on a slightly soggy bike ride. My mission? To find out how accurate the still-wet behind the ears, sub-$300 wearable is. 

However, before hitting the test, here's what you need to know about the new Garmin Forerunner 165 — those of you who read my initial impressions can probably skip this section and move on to the next. 

Garmin Forerunner 165 – what you need to know

The Forerunner 165 comes in two models: one with onboard storage for music for $299.99 and the other without for $249.99. 

Both options feature an easy-to-view 1.2-inch AMOLED screen, 11 days of battery life, heart rate and SpO2 tracking, a plethora of physical buttons and GPS. This all comes packed neatly inside an attractive and lightweight package with four snazzy styles to choose from. 

Garmin Forerunner 165.

The new Forerunner 165 is sporty yet refined, particularly the two colorful ones.  (Image credit: Garmin)

The Forerunner 165 sits above the entry-level Forerunner 55 and mid-tier Forerunner 265 — two of the best running watches on the market today. It also slides in adjacent to the Vivoactive 5, a similar-looking device built for more casual users.

And with that, we're off to the test!

Garmin Forerunner 165 vs. Strava – GPS test

For a lot of runners, onboard GPS is a must-have feature for any wearable under consideration. Why? It frees you up from carrying a bulky smartphone without sacrificing location and distance data. 

I'm more of a peddler than a pavement pounder, but I still appreciate the above line of thinking, even if I have a nifty Peak Design phone mount for my bike. So, when the sky cleared briefly this past weekend, I put on my finest bike helmet, strapped the Forerunner to my wrist and hit the mean streets of Seattle. 

To test the accuracy of the onboard GPS, I also ran ol' reliable Strava on my iPhone (12 Mini) for the duration of my ride. A couple of notes about the ride before we jump into the results. 

I started off the journey in a parking lot with a clear view of the sky. With the GPS on the Garmin fired up, it took about 45 seconds to find a satellite and establish a healthy connection — that connection remained solid throughout the rest of the excursion. 

Garmin Forerunner 165.

The Forerunner sports onboard GPS, a heart rate sensor and a SpO2 sensor to keep tabs on blood oxygen saturation levels.  (Image credit: Dan Bracaglia/Future)

My passage around Seattle's Lake Union and then into Interlaken Park took me through areas with skyscrapers, towering construction cranes, dense aerial electric wires, old-growth tree cover and other obstructions of the heavens. Speaking of which, the sky remained cloudy for the duration, and it rained on and off — that's Seattle in winter, for you.

Because this is a bike ride I've completed numerous times (well over 100), often while testing other fitness trackers, I have a lot of useful data points to compare the Forerunner's metrics to, including average and maximum heart rate, pace and elevation gain. 

Of course, these data points don't offer a tit-for-tat comparison, as the rides inevitably vary. But they do show roughly how the Forerunner 165 stacks up against other trackers, like two top-performing models.

Garmin Forerunner 165 vs. Strava – GPS test results

Swipe to scroll horizontally
Header Cell - Column 0 Garmin Forerunner 165Strava & iPhone
Distance9.52 miles9.48 miles
Elevation gain 577 feet534 feet
Average speed 7.9 mph11 mph
Max speed28.7 mph44.1 mph

Right off the bat, I'm impressed with the Forerunner 165 and its accuracy in the distance department. The 0.04-mile discrepancy between the two devices translates to a measly 211 feet, or three-quarters the length of an American football field (for my UK readers, that's roughly the width of 17 cricket pitches). 

Elevation gain is easy to overlook if you live somewhere relatively flat. But in Seattle, hills are a part of life and also a major part of my workout routine. So, accurate post-ride elevation data is a must. 

Garmin Forerunner on the wrist.

Distance data between the Forerunner and Strava was a near match.  (Image credit: Dan Bracaglia/Future)

There's an onboard altimeter in the Forerunner 165, and it clocked my altitude gain as 43 feet higher than Strava. Without a third GPS-equipped device, it's difficult to know which is more accurate. However, my gut says the Garmin number may be a tad inflated. Still, this discrepancy isn't enormous. 

On the flip side, Garmin clocked a much slower overall pace for my ride than Strava at 7.9 mph. Given my past several rides have been in 10 and 11-mph neighborhoods, Garmin's speed struck me as slow. 

One possible reason is I stopped numerous times during the ride to snap photos of the watch. Strava automatically pauses tracking during these moments. Garmin does not, or at least not by default. But further investigation is needed. 

Garmin Forerunner 165 – heart rate accuracy

Swipe to scroll horizontally
Header Cell - Column 0 Garmin Forerunner 165Fitbit Inspire 3Polar Vantage V3
Average heart rate148 bpm159 bpm160 bpm
Max heart rate 181 bpm181 bpm 179 bpm

To get a sense of heart rate accuracy, I looked back at a recent bike test between the Fitbit Inspire 3 and Polar Vantage V3 along the same bike route (and under similar weather). 

While we mustn't read too deeply into these numbers — some days I feel like Beryl Burton and others like Dan Bracaglia — the fact that all three devices recorded nearly identical maximum heart rates for the ride is encouraging.

The lower average heart rate can again likely be chalked up to my numerous stops and starts, which dragged things down. 

Garmin Forerunner 165 on wrist looking at post workout stats.

Heart rate readings matched with recent trends recorded by similar devices for this route.  (Image credit: Dan Bracaglia/Future)

Garmin Forerunner 165: So far, so good

Of course, this is just one quick assessment of the Garmin Forerunner 165 and its tracking prowess. In the coming weeks, the TG fitness team will be putting it to the test in a variety of other scenarios, from rainy runs to mountain hikes to midafternoon naps. 

For now, I'm feeling pretty good about the Forerunner 165 and its ability to accurately and reliably track workouts. Then again, given its pedigree, accuracy should perhaps come as no surprise. 

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Dan Bracaglia
Senior Writer, Fitness & Wearables

Dan Bracaglia covers fitness and consumer technology with an emphasis on wearables for Tom's Guide. Based in the US Pacific Northwest, Dan is an avid outdoor adventurer who dabbles in everything from kayaking to snowboarding, but he most enjoys exploring the cities and mountains with his small pup, Belvedere. Dan is currently training to climb some of Washington State's tallest peaks. He's also a big photography nerd. 

  • Runner and cyclist
    I've got to say, this could be the laziest review of a fitness tracking device I've ever seen.

    You compared it to something that is notoriously innaccurate - surely you should compare two items which actually have the same function. I don't try and add things up using a shoe and then claim it does a pretty bad job as a calculator.

    You didn't bother changing the settings to match between devices, and instead just said that "further investigation would be needed".

    And you compared heart rates from completely different activities???

    This is an abomination of a review, please remove it before too many people read it. At this point it is probably better to just let ChatGPT take over if you aren't going to bother doing it properly.