Need help w/ inaccurate distance tracking

DanKorte

macrumors newbie
Original poster
Apr 9, 2019
7
0
Apple Watch newbie here! I have a series 3, 42mm, gps and I use Runkeeper. I was walking laps on a track whose total distance I know to be 3 miles. Problem is, the watch gave me "credit" for 3.58 miles, which I know is *very* incorrect. Any idea how I can adjust/calibrate it to improve accuracy of tracking distances? Similarly, I went for a walk in my neighborhood tonight, and it said I went 2.61 miles when my wife's Fitbit showed 1.95 and my car driving the same route showed 1.8. That's simply too much variance to be accurate, and I'm sure it's the Apple Watch running high. any idea what's up with that?

Thanks, all!
 

PBz

macrumors 68030
Nov 3, 2005
2,502
1,362
PVB, Florida
Did the Runkeeper app say 3.58 miles and 2.61 miles?
I would do 3-4 20+ minute runs using the stock app to allow it to calibrate. I have found that many of the apps used on the watch (Runkeeper, Nike+) can be less accurate than the stock. This would be exacerbated if you have not done the initial run/distance calibration.
 
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DanKorte

macrumors newbie
Original poster
Apr 9, 2019
7
0
Did the Runkeeper app say 3.58 miles and 2.61 miles?
I would do 3-4 20+ minute runs using the stock app to allow it to calibrate. I have found that many of the apps used on the watch (Runkeeper, Nike+) can be less accurate than the stock. This would be exacerbated if you have not done the initial run/distance calibration.
Oh, wow, okay, thanks for the advice- I actually had no idea I needed to calibrate the watch, or how to do it anyway, so thank you. I’ll give it a shot!
 

MJ22

macrumors regular
Oct 3, 2017
239
181
Mine definitely got more accurate as it calibrated and now my mile markers are all the same as they were with my old Garmin.

I would caution you about using GPS on a track though. GPS from any watch is notoriously inaccurate on a track due to the tight circle you’re making. Any GPS work by bouncing a signal back and forth from the watch here on earth to a satellite in space. When you’re on a track the watch essentially plots straight lines from point to point where the signal bounces back so the distance is never quite right. If you are in lane 1 of a track, though, this will give you a more accurate measurement of your distance the old fashioned way, as each lap will measure 400m—no GPS required.
 
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DanKorte

macrumors newbie
Original poster
Apr 9, 2019
7
0
Mine definitely got more accurate as it calibrated and now my mile markers are all the same as they were with my old Garmin.

I would caution you about using GPS on a track though. GPS from any watch is notoriously inaccurate on a track due to the tight circle you’re making. Any GPS work by bouncing a signal back and forth from the watch here on earth to a satellite in space. When you’re on a track the watch essentially plots straight lines from point to point where the signal bounces back so the distance is never quite right. If you are in lane 1 of a track, though, this will give you a more accurate measurement of your distance the old fashioned way, as each lap will measure 400m—no GPS required.
[doublepost=1554983916][/doublepost] That’s good advice about being careful with GPS on the track, but I was really using Runkeeper to track my time and log the activity, moreso than actually GPSing the distance. After all, I knew it was 3 miles. That’s why I was shocked when it registered at 3.58.

Today, I’ll use the workout app native to the watch on the neighborhood walk I know is 2 miles even, and see how that works
 

ftaok

macrumors 603
Jan 23, 2002
6,146
1,165
East Coast
When you use Runkeeper, are you sure that you have the GPS on and functioning? If the GPS is operational, then calibration won't do anything. Calibration is needed for helping with mileage accuracy when you walk/run on a treadmill or indoor track.

If you're certain that the GPS is functioning (verifiable if you can see a map), then I would suspect that you have a setting or two that needs to be checked off.

  • Settings/Privacy/Location Services/Runkeeper - should be "While Using the App" or "Always"
  • Settings/Privacy/Health/Runkeeper - make sure you allow Runkeeper to read/write to Health for whatever metric you want.
  • Settings/Privacy/Motion & Fitness - Fitness Tracking should be clicked ON and Runkeeper should be clicked ON
  • Settings/Privacy/Location Services/System Services - make sure Motion Calibration and Distance is clicked ON.

I had an issue way back where my mileage was overstated by 15% consistently. Doing the stuff above fixed it and I no longer have that issue. But it could have been un-pairing and then re-pairing the watch too, but that's more of a nuclear option.

Here is a post speaking to the issue.

https://forums.macrumors.com/threads/series-2-gps-inaccurate.2131895/#post-26337426
 
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ftaok

macrumors 603
Jan 23, 2002
6,146
1,165
East Coast
I would caution you about using GPS on a track though. GPS from any watch is notoriously inaccurate on a track due to the tight circle you’re making. .
It is true that GPS aren't absolutely accurate on a traditional 1/4 mile track, but I think you're overstating the issue.

The OP's GPS problems are in the range of 20-40% off. On a regular track, you might get a reading that's +/- 0.01 mile or so, which would be off by 4% or so.

Using the GPS at a track is not the OP's problem in this particular situation. It's perfectly fine to use a GPS device at a regular track, unless you need pinpoint accuracy.
 
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DanKorte

macrumors newbie
Original poster
Apr 9, 2019
7
0
When you use Runkeeper, are you sure that you have the GPS on and functioning? If the GPS is operational, then calibration won't do anything. Calibration is needed for helping with mileage accuracy when you walk/run on a treadmill or indoor track.

If you're certain that the GPS is functioning (verifiable if you can see a map), then I would suspect that you have a setting or two that needs to be checked off.

  • Settings/Privacy/Location Services/Runkeeper - should be "While Using the App" or "Always"
  • Settings/Privacy/Health/Runkeeper - make sure you allow Runkeeper to read/write to Health for whatever metric you want.
  • Settings/Privacy/Motion & Fitness - Fitness Tracking should be clicked ON and Runkeeper should be clicked ON
  • Settings/Privacy/Location Services/System Services - make sure Motion Calibration and Distance is clicked ON.

I had an issue way back where my mileage was overstated by 15% consistently. Doing the stuff above fixed it and I no longer have that issue. But it could have been un-pairing and then re-pairing the watch too, but that's more of a nuclear option.

Here is a post speaking to the issue.

https://forums.macrumors.com/threads/series-2-gps-inaccurate.2131895/#post-26337426
Thank you for including these settings to check. All of mine were aligned except for the last one, so I turned on Motion Calibration and Distance, and I'll take a walk later today to see if that's corrected things. Thanks again!
[doublepost=1554995424][/doublepost]
It is true that GPS aren't absolutely accurate on a traditional 1/4 mile track, but I think you're overstating the issue.

The OP's GPS problems are in the range of 20-40% off. On a regular track, you might get a reading that's +/- 0.01 mile or so, which would be off by 4% or so.

Using the GPS at a track is not the OP's problem in this particular situation. It's perfectly fine to use a GPS device at a regular track, unless you need pinpoint accuracy.

Right, I would have been okay with a 4% variance, but I'm not okay with a 3 mile track registering 3 1/2 miles. But a good point was raised about my trying to stay in the same track lane!
 

QCassidy352

macrumors G4
Mar 20, 2003
10,603
2,731
Bay Area
Is it possible you have it set to an indoor run (which would cause it to rely on the accelerometer rather than GPS)? Because those variations are waaaay more than you should be seeing from GPS.
 

DanKorte

macrumors newbie
Original poster
Apr 9, 2019
7
0
Is it possible you have it set to an indoor run (which would cause it to rely on the accelerometer rather than GPS)? Because those variations are waaaay more than you should be seeing from GPS.
I don’t think I had an indoor run setting on, because I was using Runkeeper, not the workout app. But I definitely agree with you that the variation in mileage was far greater than I should’ve been seeing!
 

oeagleo

macrumors 6502a
Feb 5, 2016
551
303
West Jordan, Utah
Thank you for including these settings to check. All of mine were aligned except for the last one, so I turned on Motion Calibration and Distance, and I'll take a walk later today to see if that's corrected things. Thanks again!
[doublepost=1554995424][/doublepost]


Right, I would have been okay with a 4% variance, but I'm not okay with a 3 mile track registering 3 1/2 miles. But a good point was raised about my trying to stay in the same track lane!
Here in Salt Lake, we have a Winter Olympic oval that was built for the ice skating competitions. The facility also has a running/walking track around the Ice Rink, that is measured to the .01 mile per 1/4 mile for each lane. That's about 13 feet per quarter mile. I've used it to calibrate the footpod on my Garmin 5+, but haven't thought to test the Apple Watch on it, although the watch does seem pretty close on my "mall walks". The distance is fairly close to what I get with my Garmin and Footpod combo. I wish we could "dial in" distance accuracy like I can with the Garmin though.
 

ftaok

macrumors 603
Jan 23, 2002
6,146
1,165
East Coast
Should be easy enough the check. Was there a map generated? If you see a map, the GPS was used. If not, then you probably had an indoor/treadmill workout selected
I don’t think I had an indoor run setting on, because I was using Runkeeper, not the workout app. But I definitely agree with you that the variation in mileage was far greater than I should’ve been seeing!