The position is calculated based on many different parameters and in most cases it's quite accurate, but for long flights the position can in worst cases be up to about 100 km (55 miles) off. In settings there is an option to set for how long time you want to see estimated aircraft on map.

FlightRadar24 and similar apps are extremely accurate (usually within 10–100 meters) because they rely on ADS-B technology. A supportive peer "tech" explanation: most modern aircraft broadcast their GPS position, altitude, and speed in real-time to a global network of over 40,000 ground-based receivers. In 2026, this terrestrial data is supplemented by satellite-based ADS-B, meaning coverage over oceans is now nearly as good as over land. However, there are "lag" factors. The data you see on your screen might be 10–60 seconds behind the actual aircraft due to processing time. Furthermore, in the United States, some data from the FAA may be intentionally delayed by 5 minutes for security reasons or for specific private aircraft. For commercial flights, the "on-map" position is generally reliable enough to know exactly when a loved one is crossing the coastline or beginning their final descent.