Why does pace differs between watch and TomTom Sports?

eliteile Registered Users Posts: 1
New Traveler
edited January 24 in TomTom Sports
After a short run of 2 km (10 x 200m on outdoor track) today I noticed something strange and annoying.
The TomTom Runner 3 had lap as training mode and I could see the average pace after each lap. The notice came spot on every lap (start/finish-line).
The lap pace the displayedwas for a few laps above 4:00 min/km (up to 4:05 min/km) but most of them below. Total average pace was 3:56 min/km.

So far so good, but when loading the activity to TomTom Sports, I noticed that myTomTom Sports showed all 10 laps as faster than 4:00 min/km. Only 1 lap above total average pace, 8 faster than total average. The sum of all averages was 30 seconds faster than total time. Rounding errors could account for +-1 s/lap. The watched and TomTom Sports showed the same distance, total time and average pace.

1. Why do I see different lap-paces when running compared to in myTomTom Sports?
2. How is it possible that sum of laps time is significant less than total time in myTomTom Sports? (it is mathematical impossible)
3. Why does TomTom modify the data from the watch when transferering to myTomTom Sports? (there are already algorithms applied to the data in the watch)

(main reason I use laps is to get the "current" pace when running is that normal "current pace" almost always is way of, but that is another topic)


  • lampard
    lampard Administrators Posts: 5,954
    Hi eliteile,

    Welcome to the Community & sorry for my late response!

    Thank you for flagging this one! I would advise you to report it to our customer support who can dig in more deeply than we can on the user forum. If possible, please provide them with a screenshot showing the discrepancies of pace between watch and TomTom Sports.

    You can click on 'Contact us' option at the bottom of this page to Phone/Email them.