The accuracy of GPS coordinates calculated by a mobile phone or tablet can vary depending on a number of factors. In general, modern mobile devices use a combination of GPS, cellular network data, and Wi-Fi signals to determine their location, a process known as "assisted GPS."
Under ideal conditions, such as being outdoors with a clear view of the sky, the GPS accuracy on a mobile device can be within a few meters. However, in more challenging environments, such as indoors or in areas with tall buildings or other obstacles that block the GPS signals, the accuracy can be significantly lower.
Additionally, the quality of the GPS receiver and the specific software used to calculate the coordinates can also impact accuracy. Some mobile devices have more advanced GPS hardware and software than others, which can result in more accurate location data.
Overall, while mobile devices can provide reasonably accurate GPS coordinates, it's important to keep in mind that they may not always be as precise as other GPS devices, such as dedicated GPS receivers used for navigation or surveying.