The Google Fitbit Edge is Google’s latest fitness tracker, and it’s designed as a halfway house between the screenless, super-cheap Google Fitbit Air and the full-fat Google Pixel Watch 5 smartwatch. Costing $179.99 / £159.99 / AU$269, it’s packing GPS (which the Air doesn’t) and Fitbit’s improved automatic activity detection, alongside the usual metrics like heart rate, sleep tracking, and estimated calories burned.
But is it accurate? That’s the big question. While we found the Google Fitbit Air accurate compared to the Apple Watch Ultra 3 and a heart rate monitor, we’ve been burned by Fitbit in the past, with some accuracy issues plaguing this device’s spiritual predecessor, the Fitbit Charge 6.
I’ve only been testing the Edge for a couple of days, but I wanted to test its mettle straight away. On my first 5km run with the new Fitbit, I compared its stats on one wrist against another wearable, the high-end Garmin Fenix 9 Pro.
The 9 Pro costs around five times as much as the Google Fitbit Edge, and has been tested against chest-mounted heart rate monitors and other premium wearables like the Apple Watch Ultra 4 to determine accuracy.
It’s worth noting that devices normally take a few days to learn your movement patterns and baseline metrics, so I was expecting some deviation in metrics such as heart rate. However, I was hoping the Google Fitbit Edge’s distance and pace information, calculatedhat would indicate the little fitness tracker is almost as accurate as the powerful Fenix 9, making it good value for money
The results
When I compare wearables during workouts, I use the average heart rate metric as a good indication of wearable accuracy. Heart rate, measured by LED-based PPG sensor arrays, is the cornerstone of wearable health tracking and a core basis of everything from estimations in sleep quality to calorie burn.
Average heart rate, which all wearables provide during a workout, is a great way to compare. While different devices use different algorithms and so forth, resulting in fluctuations in graphs, if two or more wearables show a similar average heart rate, it’s a good indication that these devices are broadly accurate.
Fortunately, the cheaper Google Fitbit Edge does cleave very closely to the Garmin Fenix 9 Pro, which I know is accurate thanks to past tests against the Frontier X2 heart rate monitor and Apple Watch Ultra 4. The Google Fitbit Edge showed an average heart rate of 156 bpm, while the Garmin Fenix 9 Pro showed an average heart rate of 153 bpm. That’s a great result for the Fitbit.
Unfortunately, the same can’t be said for the distance metric, which calculates how far I ran. During the run, while glancing at my Google Fitbit Edge, it was consistently overestimating my running speed, often showing 30 seconds or more ahead of my Fenix, and that was reflected in the final distance result. While the Google Fitbit Edge said I ran 5.45 km, the Garmin Fenix 9 Pro measured just 5.15 km— a distance of around 300 meters.
That’s acceptable over a longer race, like a marathon (there was a similar discrepancy when I ran London with an Apple Watch and a Garmin), but that’s 300 meters over 42 kilometers, not five. 300 meters on this run equates to an overestimation of around 6%, and I trust the thousand-dollar Garmin’s multi-band SatIQ GPS more than the sub-200-dollar Fitbit’s.
I will repeat the experiment with longer runs — with fewer trees — to see if I get a smaller deviation. It’s not a dealbreaker for casual exercisers, but over 5% is enough for a keen runner to choose another device. Stay tuned for more testing and a full review of the Google Fitbit Edge very soon.
