There are 2 ways of setting stride length on your Geonaute pedometer: automatically (AUTO) or manually (PERSO).

AUTO: Depending on your height, the pedometer will automatically calculate your stride length using a patented algorithm.
PERSO: For the most accurate results, you can enter your stride length manually.

To measure your stride length: Walk 10 metres, counting the number of steps you take, then use the following formula ;10 metres/number of steps = length of stride