The Apple Watch Confuses Miles and Kilometers

The Apple Watch, by default, records distances in miles, when you do a workout. You can change this, but the setting is hidden. However, the Apple Watch seems confused about which unit it is using.

I just finished a 30-minute walk on my treadmill. At 3.5 mph, I walked about 1.7 miles; this is a simple calculation. I recorded this on my Apple Watch as an Indoor Walk workout. The Apple Watch, a replacement I just received two days ago, hadn’t yet been set to use kilometers.

At the end of the workout, the Activity app on my iPhone shows this:

Apple watch miles kilometers

The Apple Watch counted the distance as 1.02 miles, which happens to be about the equivalent of 1.7 kilometers. In other words, it seems to have calculated my distance by converting miles to, well, miles, using the conversion from kilometers to miles. I’ve noticed the same thing before with indoor walks, even with the first Apple Watch I had, which I did set to kilometers.

It’s quite clear that this is a simple conversion error. Walking at around the same pace outdoors, the Apple Watch shows my pace to be around 20 minutes per mile. (Alas, while you can change the unit of measurement for distance, you can’t change it for pace, or for what displays in the Activity app on the iPhone.) When I do an indoor walk, it shows the pace, as you can see above, at around 30 minutes per mile. Yet if it’s simply counting steps in an indoor walk – since it can’t use GPS – and knows the length of my stride, this should be the same pace. Unless some developer at Apple introduced in error in calculation.

This isn’t something that should be too hard to get right. I calibrated the Apple Watch outdoors, as one should, so it could learn the approximate length of my stride. It should take that into account during any activity during the day, but also during workouts that involve movement. Yet it gets it wrong, in what seems to be just a dumb bug. This is another disappointing example of the Apple Watch’s inaccuracy as a fitness tracker.

8 thoughts on “The Apple Watch Confuses Miles and Kilometers

  1. Um, the title says “Doesn’t Confuses”. Unless you’re being ironic, you might want to fix that.

    And it is disappointing that Apple Watch would have an error in such a basic thing.

    • LOL. Originally, I had “Doesn’t Understand.” I changed to “Confuses,” but forgot to delete the other word. But it was actually a good slip, because that’s pretty much what the Apple Watch is doing with units. 🙂

  2. Um, the title says “Doesn’t Confuses”. Unless you’re being ironic, you might want to fix that.

    And it is disappointing that Apple Watch would have an error in such a basic thing.

    • LOL. Originally, I had “Doesn’t Understand.” I changed to “Confuses,” but forgot to delete the other word. But it was actually a good slip, because that’s pretty much what the Apple Watch is doing with units. 🙂

  3. Same issue here… using it for indoor runs (on a treadmill) the watch looks like it is always tracking kilometers and is spot on doing so…. the issue is the read out is in miles…

  4. Same issue here… using it for indoor runs (on a treadmill) the watch looks like it is always tracking kilometers and is spot on doing so…. the issue is the read out is in miles…

  5. I’ve been going crazy trying to figure out why my Apple Watch records distance so poorly on treadmill runs despite my efforts to calibrate it. No matter what I do, the Watch always seems to record a distance figure for a run that it approximately 2/3 of the distance (in miles) that the treadmill says that I ran. Something about the fact that it was showing 2/3, or about 0.6 of the correct mileage seemed important, but until I came across this blog post from over a year ago I hadn’t made the connection. The Watch is recording/displaying the distance inaccurately by doing something like multiplying the actual number of miles ran by 0.62 to convert it to kilometers (even though I didn’t ask it to) but then labeling the result as “miles”. If I run 3.1 miles on the treadmill (5K), the watch will display something like 1.9 miles.

    As far as software bugs go, this one seems sloppy, but hardly unprecedented. The thing that blows my mind, though, is that my watch running WatchOS version 2.2.1 in June 2016 is doing the same thing described in this blog entry from May 2015 when WatchOS 1.x was still in use. And even weirder, further Googling shows almost nobody else discussing this on the web. Does the problem not happen to everybody using their Watch on treadmill runs? Or has everybody just accepted the inaccurate readings and not noticed the underlying display bug?

    If Mr. McElhearn happens to see this comment, I’d be curious to hear if a solution was ever found or his thoughts on how the problem persists over a year later. Thank you!

  6. I’ve been going crazy trying to figure out why my Apple Watch records distance so poorly on treadmill runs despite my efforts to calibrate it. No matter what I do, the Watch always seems to record a distance figure for a run that it approximately 2/3 of the distance (in miles) that the treadmill says that I ran. Something about the fact that it was showing 2/3, or about 0.6 of the correct mileage seemed important, but until I came across this blog post from over a year ago I hadn’t made the connection. The Watch is recording/displaying the distance inaccurately by doing something like multiplying the actual number of miles ran by 0.62 to convert it to kilometers (even though I didn’t ask it to) but then labeling the result as “miles”. If I run 3.1 miles on the treadmill (5K), the watch will display something like 1.9 miles.

    As far as software bugs go, this one seems sloppy, but hardly unprecedented. The thing that blows my mind, though, is that my watch running WatchOS version 2.2.1 in June 2016 is doing the same thing described in this blog entry from May 2015 when WatchOS 1.x was still in use. And even weirder, further Googling shows almost nobody else discussing this on the web. Does the problem not happen to everybody using their Watch on treadmill runs? Or has everybody just accepted the inaccurate readings and not noticed the underlying display bug?

    If Mr. McElhearn happens to see this comment, I’d be curious to hear if a solution was ever found or his thoughts on how the problem persists over a year later. Thank you!

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