The only way to find out how many flights you will get out of an RX pack is to fully charge the pack and then fly as many filghts as you can measuring the pack between each filght as every filght is different (different servo use). You will have to do this with every plane and battery setup as they are all different Then you will know haow many flights or total flight time you can get. Doing the measurement on the ground will be a lot less than in the air as there is no vibration from engine or load on the flight surfaces.

Cheers