The conversion
Divide the MB value by 1,000. 2,500 MB is 2.5 GB. 1 GiB is 1,024 MiB, which is a larger byte count than 1 GB.
Which system to use
Use decimal KB, MB, and GB when you are matching a label that counts by thousands. Use binary KiB, MiB, and GiB when a spec counts by 1,024. Do not add the two together as if they were the same unit.