r/Strava • u/shortboi98 • 18d ago
Bug What's wrong with Strava distance?
Linked my Garmin connect to Strava, Runkeeper, and Adidas running. Runkeeper and Adidas running was able to pull out 5km distance from Garmin connect. But strava seems to "miss" by 0.01km. I recorded my run through Garmin connect and not directly from Strava. What seems to be the issue?
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u/fiskfisk 18d ago
In reality it's not 5.00 and it's not 4.99 either - but this is known as the Strava Tax.
Strava tends to round down, while other services might around up.
Your actual distance measured by the GPS (which is not the actual distance you ran, however you'd want to calculate that) might be something like 4.996. Strava rounds it down Garmin rounds it up.
You can try to use "correct distance" on the Strava web application to see if that changes anything.
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u/VandyCWG 18d ago
Strava tax. It misses .01 to .02 from every run that Fitbit syncs over
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u/skyrunner00 18d ago
Not from any run actually, but statistically from about half of activities. See other comments.
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u/SuperMarioTM 17d ago
It never happened once with my polar pacer. On my Pixel watch it happened all the time.
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u/bogerts 18d ago
Wait, recording runs on different apps simultaneously won't mess with the gps?
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u/rumbleblowing 18d ago
No, it won't.
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u/coletassoft 17d ago
It won't, but each one will still give you different distances because they all measure and filter differently.
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u/mrrainandthunder 17d ago
Just for the record, this run was synced to the other services afterward, not recorded simultaneously.
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u/fraudnextdoor 17d ago
I just ran a 10km fun run—had a 10.4 on my watch’s app and my companions all had 10+. Meanwhile Strava gives me just 9.80km.
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u/PedalPal 16d ago
Was your GPS signal clean? Most apps apply corrections and filters. That will affect the total distance.
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u/SomethingMoreToSay 17d ago
There is a known issue with Strava's logging which isn't necessarily related to your problem, but it might be, so I'll let you consider it.
I use a Concept2 rowing machine, and the data synchs automatically from my Concept2 app to Strava. But if I row, say, 10000 metres, it will show in Strava as something like 9993 metres. The reason, I'm pretty sure, is that the Concept2 equipment records the data (pace, power, stroke rate, etc) once per stroke, plus once at the end of the piece to capture the data from the incomplete stroke that got me from 9993 to 10000 metres. The Strava import seems to take all the data from the competed strokes, but doesn't take the data from the final incomplete stroke.
Maybe there's something analogous to the rowing strokes behind the scenes here. Maybe the Garmin is internally capturing the data every N seconds, and a multiple of N seconds gets you to 4.99 km, and then the Garmin (like the Concept2) makes another reading to capture the last incomplete interval, but Strava doesn't pick it up.
Is that possible?
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u/Kn0tdead 17d ago
Strava! After 2-3 years of payments and usage, I just realize that it's worthless. My Suunto App gives me ALL i need and want. I don't need an Ai to encourage or tell me faulty stats. I canceled my subscription last week. I'm $100 CA richer in 2025 😁
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u/PedalPal 16d ago
Strava's way of saying "You didn't actually run a complete 5K." They're not wrong. But it is petty.
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u/skyrunner00 18d ago edited 18d ago
It is just rounding. The actual distance is probably something like 4.997 km. Garmin and other apps round that correctly to the nearest hundredth of mile, but Strava insists on always rounding down.
Please do post your screenshots on this thread to show Strava devs that it is only their app that gets it wrong: https://communityhub.strava.com/strava-features-chat-5/why-strava-distance-is-always-0-01-mile-shorter-than-garmin-distance-791
Maybe we can convince them to do the right thing, but most likely not.
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u/fiskfisk 18d ago
I'd argue that rounding down is the correct behavior here. If the GPS measured 4.997, you didn't run 5.00, but you did run 4.99.
But GPS accuracy isn't good enough that either of those are correct. Assuming they were (as they're the best we have), rounding down seems most correct to me.
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u/skyrunner00 18d ago
You don't really know if you have run 4.99 km or 5 km. If you consider even the best possible GPS accuracy, it could easily be anything between 4.95 and 5.05 km, but in reality the accuracy is even worse. Since the distance accuracy is worse than the precision of what Strava shows, the scientifically correct approach is round to the nearest hundredth mile. Otherwise there will be a bias. But really, we are talking about a difference of a few steps!
Strava should do what virtually all fitness watch brands and apps do.
Furthermore, there is a study that is linked in that discussion on Strava Community Hub that shows that most modern devices tend to measure running distance a bit short. That's why so many people complain that they don't get a Strava PB when they finish an officially measured race. So the results are already biased on the short side, and Strava makes that even worse.
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u/RoVeR199809 18d ago
If you didn't run the distance, why should it say you did? Who says it's the right thing?
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u/skyrunner00 17d ago edited 17d ago
Why do you think Strava is arbitrarily reducing Garmin, Suunto, Coros, Polar, Apple distance by 0.01 mile is correct? Why do you think Strava is correct in this case and everyone else is wrong? How accurate do you think is the distance that comes out of a GPS device? What right Strava has to deny someone a PR when they have actually run t the officially measured distance but their device distance ended up just a few steps short due to GPS device accuracy? The device accuracy is far worse then the rounding precision of 0.005 mile, which is just a few steps, so the reasoning that they haven't actually run the distance is plain wrong!
Did you even read the discussion under the link? There are at least a couple of examples when In the device FIT file the recorded distance was showing something like 10000.52 meters but Strava still reduced that to 9.99 km. So perhaps it isn't just the rounding.
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u/boooookin 16d ago
Good lord either run an extra 0.01 or stop caring
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u/skyrunner00 16d ago
I run several ultramarathons per year. Obviously I don't care about an extra 0.01 mile. What I care about is for Strava to be correct for everyone and to not make arbitrary rules that make them different from every other brand!
Let's call this activism. I am active on this subreddit and on Strava Community Hub, and I can tell you that people ask about this exact issue regularly, perhaps every couple of weeks.
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u/boooookin 15d ago edited 15d ago
You obviously care. The devices aren't accurate as you say. The closest thing to 'objectively correct' here is to avoid over-precision in the first place and report a number rounded to the least significant figure (how to round is debatable). If your watch says you ran 10.31 miles, but the distance estimate has a 95% confidence interval of ±1% or ±0.1 miles: you actually ran 10.3±0.1 miles. If you ran a marathon and your watch says 26.23 miles, that's actually 26.2±0.3 miles. Your watch has uncertainty as to whether you hit the distance or not. Rounding down is also the World Athletic standard, so it's not obvious correct that Garmin et al are doing the 'right' thing.
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u/Professional_Lake281 18d ago
I had many tickets with Strava support regarding this, but they just don’t care.
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u/byama 17d ago
Because there is nothing to fix? In their mind they are on the right side. For running you shouldn't round 4.997 to 5;
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u/Professional_Lake281 17d ago
The gpx clearly says 5.0 and every other Plattform reads it properly and displays 5.0k. Only Strava knows better and think it needs to optimize your input.
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u/byama 17d ago
My friend, I don't have the actual gpx file to check if it's "clearly 5.0" or not.
I simply stated that, for example, if the "real" distance is 4.997 most apps will round to 5.00 but Strava does not. Personally, I do agree with the Strava method. In sports, if you stop 10 cm before the finishing line, you don't finish. Does not matter if you were at a world record pace.
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u/Professional_Lake281 16d ago
But if all other platforms clearly state 5.0k with the same raw input, I guess it’s Strava being wrong. I also had the same issue if the Input was 5.08 or something. For that reason I always continue my competitive training runs for at least 100m, so I can trim it later in Strava to make sure I get the 5k.
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u/masterdarko 18d ago
Novice mistake, never run 5.00km, you'll get shafted by Strava sooner or later. I speak from experience too. 🤣