Depending on your local traffic, the receiver will typically upload 40MB per 24 hours to the Flightradar24.com servers. In locations where MLAT plotting is more prevalent, the uploaded data can be higher, averaging up to 300MB per 24 hours.
MLAT will be more prevalent in dense traffic areas where aircraft don’t transmit positional data. For example, in or near larger cities in the USA and close to major airports in Europe.
Please bear this in mind if you have a monthly Internet upload limit.