Power uping 100% IV
I am using a iv calculator and I was wondering if I powered up my 100% iv would it lose and iv. I did it to a 83% and it went down to 82% so I wanted to make sure before.
Answers
The percentage shown on an IV calculator is just the average IV out of all the possible combinations. IVs are discrete, you cannot have half an IV point, so any small percentage differences are meaningless and are due to rounding.
Example a Pokemon with 40/45 IVs would have 88.8% of the maximum IV bonus, some may refer to that as 88%, others 89% but that 1% doesn't matter, because at the end of the day the IV total is still 40/45.
The IVs of a Pokemon can only change if it is traded. That's it. Your 100 is a 100 forever! The reason your "83" went to an 82 is most likely because the calculator wasn't able to pinpoint the exact ivs, and it most likely had it narrowed down between either 82 or 84 so it split the difference and called it an 83. Once you powered it up, the calculator was able to determine for sure that it was (and always had been) an 82.
I think that I know what you're getting at. I have a 14/15/15 Kyogre (98% for all intents and purposes) that has levels where I've seen it show as low as 96% because it's calculating based on potential max CP, and the loss of 1 Atk weighs heavier on CP than HP or Def would.
Don't worry, your pokemon never actually looses IVs, the calculator is just telling you the % your current CP is when compared to a 100% of the same level.