Method for calculating the activity of a user, said method being implemented by a personal activity monitor (1) intended to be securely associated with the body of the user, and by a smartphone (2) equipped with a geolocation function, exchanging data over a wireless connection, the method comprising the steps of: -a- the activity monitor detects and counts the steps of the user, -b- the smartphone determines a first geolocation (A1) at a first time (T1), -c- the smartphone determines a second geolocation (A2) at a second time (T2), -d- one of the two devices (1,2) calculates a distance traveled D12 between the two geolocations (A1,A2), -e- one of the two devices (1,2) calculates, based on the distance traveled D12 and the number of steps taken between the two geolocations (A1,A2), the average stride and/or average step of the user.
