It seems like you are trying to determine capacities of your used batteries in order to make a decision if you should replace them or not.
You can look up the original capacities of most commonly used batteries by searching this forum or by browsing some reference resources such as these:
You would also need to measure the remaining capacities of your used batteries using an analyzing charger such as Opus BT-C3400 V2.1:
Then you would use this formula to determine the remaining capacity percent:
Remaining capacity percent = remaining capacity in mAh as measured by analyzing charger/original capacity in mAh as listed on BLF web site.
For example: if an analyzing charger reads the remaining capacity of 2405 mAh and the original capacity was 3200 mHh, the remaining capacity in percent is 2405/3200 = 0.7515 or 75.15%