I’ve only recently started using a GPS to log my rides on Strava and noticed yesterday, that the distance and elevation are a fair bit lower on Strava than the data on the GPS.
Does Strava just import the coordinates and work out these values for itself or am I missing a trick? (I’m just manually adding the .fit files from the activities folder.)

it does a fit to the floor map type thing, depending on your GPS the height gain can be the most unreliable of the stats.

I think strava does its own algorithm. It’s pretty consistent; when I do my regular ride it’s always within a few metres.

One of my mates uses a garmin and it often disagrees by loads from the strava figure. No idea whose is best.

Mines a basic Garmin Edge 200. They differ by about a kilometer distance and about 300m climbing.

Strava calculate their own elevation based on the GPS trace and an elevation map. Probably because most phones and some GPS devices are poorly calibrated or inaccurate at elevation. Of course, that doesn’t always get it right too, depending on how accurate the GPS trace is.

As for distance, no idea there. Similar services tend to compress your uploads by smoothing the trace (reducing every four data points to their average, for example) which can lower the distance by removing very small movement deviations which add up to a noticeable difference over a longer period of time. No idea if Strava do that or not.

Thanks for the replies. No big issue, but I was surprised as I just assumed Strava just read all the data exactly as on your device.

I’ve got the same setup franki and it’s always been a bit different between the Garmin and Strava for both distance and altitude. I’d take Strava as the “gold standard”, as the whole point of it is to compare yourself against others (and yourself). I’m sure I read somewhere that Garmin acknowledge altitude is a bit flaky and I suspect its recalculated by most services you’d upload to anyway (Strava, MapMyRide, etc).

If you have a Garmin with an Barometric Altimeter then it will be more accurate than one without.

Using a phone etc GPS points are mapped and estimated from databases…..the BA, assuming you have calibrated it, is a bit cleverer than that.

There is a piece on it on the Strava ZenDesk

As others have said – unless you have a Garmin with a barometric altimeter it won’t be very accurate.

My Garmin Edge touring over-estimates by approx. 30% on height gain, which Strava then corrects.

and I suspect its recalculated by most services you’d upload to anyway

no need to suspect.
it is.

the most the data file has is the altitude reported at each data point. some just add up all the positive differences between 2 points, and subtract all the negative (everytrail used to do this). others try to smooth it out a bit (strava maybe). others smooth it out a lot (endomondo iirc).

ride along a flat path next to a canal in holland, and what’s your altitude change? I say <1m end to end. Garmin with baro alt may fluctuate +/-1m or 1ft every few data points, and report a cumulative altitude gain/loss. Phone running strava or anything else with GPS altitude may vary more, but get filtered back down to virtually 0. Garmin device and the recorded Garmin data file processed by whatever website will definitely differ, simply due to the above.

Strava for me on my phone always read altitudes higher than what’s on the map.