Miscalculation of Ascent/climbing

khylan Registered Users Posts: 1
New Traveler
edited January 24 in TomTom Sports
Earlier today I completed a bike ride and the summary showed ascent of 2600' with my Spark Cardio + Music watch. But when I manually add up all the ascents from stats view I come up with only 1900'. Huge difference! I've had this issue all year. I also ride with a bunch of guys using Garmin computers, and I'm always reporting 20-30% higher climbing feet than they do. And when looking at rides I've planned and then ridden using Ride with GPS, my TomTom always reports much higher ascents. There is a bug in your calculation of ascent- pls let us know when the fix is ready. Thanks.


  • Raykad
    Raykad Registered Users Posts: 21
    Master Traveler

    this is caused by the Digital Elevation Model that TomTom uses. It's different from what Garmin and other manufactures use as it's dependent on what company they bought the map/environemtn data from (or from what them themselves have acquired).


    Once you upload the activity it will correspond to the data that TomTom has, recalculate it and therefor not take in to the exact account what your watch has recorded as the MySports database wants to refer it to what information it has and the GPS data it has acquired, which in layman terms could tell you that you are cycling a slope downwards when you were actually going upwards.

    Not sure if there will be a fix for this unfortunately... But hope this makes a bit more sense :).
  • tfarabaugh
    tfarabaugh Posts: 16,943
    Top add to the prior response, TT counts all changes in elevation and doe not factor out minimal ones. So even if you are on an apparently flat road you may have ascents of a meter or two. Many watches filter these out but TT counts all elevation change, even small fluctuations in an otherwise seemingly flat ride. This is not going to change, particularly as TT left the industry and laid off its Sports Division months ago, all development is done on the TT watches.

    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.