Last weekend, I put on five fitness smartwatches and drove to Mount Diablo State Park in California and hiked about 2,100 feet to the summit. Why? Determine which smartwatch brand (Apple, COROS, Garmin, Polar, or Samsung) tracks elevation most accurately.
Most high-end smartwatches come with a barometric altimeter that can determine your elevation gain during outdoor workouts. Altimeters use changes in air pressure coupled with GPS data to calculate changes in altitude. But some are more accurate than others, and most brands don’t allow you to manually calibrate the starting position.
I’ve been wanting to test this since last year’s experiment, where I walked 6,000 steps wearing six smartwatches to see which one came closest to the real number. Since then, I’ve done a few more multi-watch GPS accuracy tests for review, but these were two-dimensional tests: when my watch told me I climbed X feet or Y feet, I never knew it had How precise. stairs.
For my testing, I chose three watches I’ve already reviewed – the COROS PACE 3, Garmin Forerunner 965, and Samsung Galaxy Watch 6 Classic – as well as two watches I’m currently reviewing: the Apple Watch Ultra 2 and Polar Vantage V3 .
Apologies to those hikers I didn’t bring with me from my favorite brand; my arms are skinny but there’s only so much room. It’s more than enough time to charge and install five watches, and they give me plenty of side-viewing on the road.
Plus, some of my favorite wearables (like the Fitbit Charge 6) don’t have altimeters at all, which means their elevation data can’t be trusted beyond GPS estimates.
Thankfully, you can easily test the accuracy of your own smartwatch if you want!
Just pick a hike on a site like Alltrails, such as the Summit Trail hike to Mount Diablo, and note the minimum and maximum elevation, as well as the total elevation gain. Then, hike it yourself and compare the watch’s results with reality.
The table below is the results of my smartwatch altitude accuracy test:
| Device name | starting height | maximum altitude | total altitude gain |
|---|---|---|---|
| Accurate GPS data (AllTrails) | 1,770 feet | 3,849 feet | 2,139 feet |
| Apple Watch Ultra 2 | 1,779 feet | 3,873 feet | 2,147 feet |
| Choir Pace 3 | 1,736 feet | 3,825 feet | 2,231 feet |
| Garmin Forerunner 965 | 1,761 feet | 3,841 feet | 2,231 feet |
| Samsung Galaxy Watch 6 Classic | 1,509 feet | 3,606 feet | 2,026 feet |
notes: You may notice that rows of data are missing. This is because on the way down from Mount Diablo, my Polar Vantage V3 crashed, showing an infinite loop of Polar logos, then factory reset itself when I got home. Reddit’s Polar subreddit shows that others have encountered similar issues in the past.
Luckily, I took a photo near the summit showing my elevation at the time (3,729 feet) and total gain (2,018 feet). Add in the 100 feet or so of climbing, and the Vantage V3 is probably pretty close to what my other watches indicate; I just can’t provide accurate data, especially without a starting elevation. I’m really disappointed that this glitch messed up my testing!
Determining the “Best” Smartwatch Altimeter
We have three metrics to help determine which smartwatch is best for altitude accuracy. Let’s start with minimum elevation, which is the initial automatic calibration the smartwatch generates when you start a workout.
Garmin and Apple are miraculously juxtaposed here, nine feet apart. The COROS is 34 feet shorter, 25 feet shy of the Garmin, but that’s nothing compared to the Samsung’s score, which is 261 feet shorter.
Moving on to the maximum elevation, the Garmin beat the official summit number by eight feet.Basically, even if the Garmin is off by a few yards each time, the difference between the minimum and maximum (2,080 feet) is just one foot Contrary to the official figure (2,079 feet).
The maximum result from COROS is 3,825 feet, which is 24 feet shorter; however, if you look at the total difference (2,089 feet), you’ll see that this is only 10 feet different from the satellite data, which most hikers will be happy to accept .
Apple’s maximum elevation data had me floating about 24 feet above Mount Diablo, for a total altitude difference (2,094) of 15 feet. WatchOS fans probably won’t mind this minor difference considering all the smart features the Apple Watch Ultra 2 offers compared to most fitness smartwatches.
You could also argue that the Galaxy Watch 6 Classic’s total elevation difference (2,097 feet) is impressive, but the maximum elevation is just as outrageous as the minimum.Samsung have The Alti-Barometer app on the Galaxy Store can solve this problem, but it’s designed for Tizen OS and won’t work properly with Wear OS.
Finally, we can look at the total elevation gain, which (for clarification) is different from the subtracted sum above because you gain additional elevation every time the path moves up or down.
At first glance, the Apple Watch Ultra 2 exceeds this metric, claiming just 8 feet more. The problem is that I did go up and down the stairs at the top of the mountain a few times and also walked some trails with small hills which added unnecessary ups and downs.
So while both the Garmin Forerunner 965 and the COROS PACE 3 climbed 92 feet longer, I wanted to know if my actual results were somewhere between those two and the Ultra 2. The fact that they had exactly the same results was another surprise.
The great thing about the latest Garmin Forerunner watches, the PACE 3 and Apple Watch Ultra 2, is that they all have dual-frequency GPS tracking. If the mountain you’re climbing blocks the view of the nearest GPS satellite, they can use another satellite to calibrate your position.Since the watch uses GPS to enhance the altimeter results, this means you’ll likely get something closure to get accurate results.
If you’re using a GPS-only watch (such as the Galaxy Watch 6 Classic), your altitude results may end up being more dicey despite the built-in altimeter.The wrong starting altitude probably doesn’t matter from a practical perspective, but in fact it underestimated my altitude get At least 100 feet is inexcusable.
I hope Samsung solves its fitness issues in 2024 and the Galaxy Watch 7 Pro becomes more trustworthy. But at the same time, I’m very pleased with how the Garmin, COROS, and Apple performed in my testing. Garmin wins in altitude specific numbers, Apple (maybe) wins in altitude gain, and COROS is very close in both areas.
Rather than backing one clear winner, I want as many brands as possible to give you accurate results so hikers and cyclists have plenty to choose from.
if If you’re currently looking for a new smartwatch, cycle computer or handheld GPS, my advice is that you don’t take for granted the altimeter in a spec sheet as a sign of reliability. Keep your receipts, hit the road with your new watch as soon as possible, and be sure you get pretty accurate results.