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.