Kms kloppen niet
Kms kloppen niet
When you do not start any Activity, the watch measures the distance by an estimate based on the number of steps and the average stride length. You have to start the Walking, Hiking, Running (or whatever else) Activity to actually start the GPS device. Type the name of your watch into the search box at YouTube, and you will get plenty of videos nicely and clearly demonstrating its basic use.
OK, you did not tell that you use the Vivosport. This device does not have GPS, so it cannot measure the distance. It can only estimate the distance by the stride length. By default the algorithm uses the average stride length set on the basis of your height, age, and gender from your user settings. You can calibrate and set a custom stride length. As I already wrote, on YouTube, you can find plenty of videos explaing the use. For example the following one demonstrates how to calibrate the stride length on Vivofit (I guess it may be pretty the same on Vivosport):
https://www.youtube.com/watch?v=Er1duXK4zZY
For further questions, please use the Vivosport forum, and post preferably in English. Most users won't bother reading and translating your questions in Flemmish, hence you'll have little chance to be helped.