# Wrong distance calculation

koplov
Posts:

**4***[Apprentice Traveler]*
I am connected STRAVA to my TOMTOM sports app so every activity on my watch is uploaded to STRAVA.

On my last run, I saw a big difference between the running distance in the TOMTOM watch (5 KM) and the running distance showed on STRAVA (4.6 KM) on the same activity which was uploaded from the TOMTOM sport app.

I tried to check whether there was a problem with the uploading of the activity so I downloaded the GPX files both from TOMTOM sports and from STRAVA and I saw that the longitude and latitude points are the same.

Then I applied the distance calculation formula on the longitude and latitude points and got that I run 4.6KM and not 5KM.

This means that for some reasons the watch calculate the distance wrong.

Does anyone else encountered this problem?

Does anyone knows how to fix it?

On my last run, I saw a big difference between the running distance in the TOMTOM watch (5 KM) and the running distance showed on STRAVA (4.6 KM) on the same activity which was uploaded from the TOMTOM sport app.

I tried to check whether there was a problem with the uploading of the activity so I downloaded the GPX files both from TOMTOM sports and from STRAVA and I saw that the longitude and latitude points are the same.

Then I applied the distance calculation formula on the longitude and latitude points and got that I run 4.6KM and not 5KM.

This means that for some reasons the watch calculate the distance wrong.

Does anyone else encountered this problem?

Does anyone knows how to fix it?

0

## Comments

14[Apprentice Traveler]However, I can't see how can you declare that some measured data like time can differ (since my running speed is not close to the speed of light).

The same goes for distance calculations. Is there 2 different ways to calculate the distance between 2 GPS waypoints?

Isn't it a relatively simple and known geometry equation of calculating the distance between 2 points on a sphere?

As I said before, I already applied the formula my self on the GPS waypoints data and received the same distance as in STRAVA.

By the way, I also checked it with ENdomondo and received the same distance as in STRAVA.

15,773SuperusersI 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.

15,773SuperusersAre you a TomTom employee? Your response (the use of we) makes it sound like it, but your identification tag does not indicate you are an employee.

1[Apprentice Traveler]