App Store size limit calculation details

[PISD Support]

Most developers are aware that the allowed size of an application for download via normal phone comms has been upped to 20Mb, however few people I've talked to seem to understand exactly how this size limit is calculated.

The size of an application in the AppStore is equal to:
Size of the app binary (uncompressed – ie. file that ends in .app) + rest of the files in the app bundle (ie. data and resources) which was compressed with the apple zip algorithm (ie. done on a mac)