Same run different stats

Linsmb Registered Users Posts: 1
New Traveler
edited January 24 in TomTom Sports
I have just been for a run with my mum who als has a Tomtom watch. Our stats are very different despite running next to each other the whole way.

I ran 6.6km with 7.12min pace
She ran 6.16km with 7.42min pace

I understand there being a slight discrepancies but that's quite different considering we were next to each other the whole way.

Why does this happen? Are our watches not working properly? They are both up to date


  • tfarabaugh
    tfarabaugh Posts: 16,935
    That is to be expected to an extent. The nature of GPS is that each data point collected is only accurate to within 15-30m of your actual location. The watch collects the data points and then tries to figure out a route using them (considering that some points may overlap or duplicate). The watch then smooths the data to come up with the most reasonable route taken according to the algorithm it is programmed with. This is why every watch, even two of the same model, will come up with different distances, as they are collecting different GPS data. One watch may have dropped signal for a bit or picked up extraneous points as well. Since the distances are different the paces will also be different. You can export a tcx or gpx file from MySports and there are plenty of resources on the web which will calculate a distance from it for comparative purposes. A few I have used are:

    I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question.