A GPS tracker can use surprisingly little mobile data if it sends compact location records, but there is no universal “megabytes per day” figure. Data usage depends on how often the app uploads, what each record contains, protocol overhead, retries, map downloads and whether multiple points are batched together.
The phone receives GNSS satellite signals directly. Mobile data enters the picture when an application communicates with a server or downloads online content. This distinction matters because reducing the tracking interval does not stop satellite reception—it changes how much information the application records or transfers.
For the basics, see Does GPS use mobile data?.
A basic record can contain latitude, longitude and timestamp. Real trackers may additionally include accuracy, altitude, speed, heading, battery information, device state or sequence numbers. The network request then adds HTTP/TLS or other protocol overhead around the payload.
A ten-byte difference in a coordinate field is therefore not the whole calculation. Connection setup, headers and acknowledgements can matter, especially when sending many tiny independent requests.
Imagine one configuration uploads every ten seconds and another uploads every five minutes. Even if each request is equally small, the first creates thirty times as many upload events. A fast interval can be useful for a detailed moving trail, but it is unnecessary for every use case.
A parked vehicle, occasional family check-in and cycling route logger do not all require the same frequency. Pick the lowest rate that still answers the question you care about.
When connectivity is intermittent, storing several points and sending them together can be more efficient than opening a separate transaction for each coordinate. It also lets a tracker survive temporary dead zones. The server should preserve the original capture timestamp for every point so a later batch does not distort the route.
This is also why a short outage does not have to mean lost history.
If the same phone is displaying satellite imagery or continually downloading detailed map tiles, those visual assets can dominate network use. The remote viewer's browser may also consume map data, but that is separate from the tracked phone's upload allowance.
When measuring a tracker, distinguish the application's background data from the data used while you actively browse its map.
A real measurement on your own network and app version is much more useful than a fixed estimate copied from another phone.
For international travel, you can let the phone record offline and synchronize on Wi-Fi if real-time viewing is not required. If live sharing matters, choose a data plan that leaves comfortable headroom for tracker traffic plus maps and other phone use.
Read GPS tracking abroad for practical preparation.
Reducing network use is useful only if the resulting trail still serves its purpose. Extremely infrequent points can miss short trips and make route lines misleading. Conversely, a hyper-frequent upload can waste battery and data without adding useful information.
Measure route quality, battery use and data use together. The best configuration is a balance, not the smallest possible number in one column.