The current circulating supply is 756 billion KIN.

Over time, this will increase to a maximum of 10 trillion KIN (as funds are unlocked to the Rewards Engine).
The only 'formula' that applies here is:

market cap = price per coin * circulating supply

For the purposes of this explanation, consider market cap as a constant. If the supply goes up, the price comes down, and vice versa, but the market cap does not change. So if you take two coins which have the same market cap, but one has a larger supply, that coin will have the smaller price per coin.

What does that mean? It means if you buy $100 of the coin with the lower price, and your friend buys $100 of the coin with the higher price, you’ll have ‘more’ coins. But you don’t ACTUALLY have ‘more coins’, because you will own the same % of coins out of the circulating supply as your friend does. Remember that all cryptocurrencies are divisible by many decimal places. The integer number does not matter. Only your percentage owned out of the supply matters.

In the real world, the only difference between a large supply and a small supply is that we will be able to talk about KIN in terms of “one thousand kin” or “one million kin”, instead of trying to talk about it in terms of “0.00000123 KIN” like with many other cryptocurrencies. This is easier for mass market users to understand.

Also, in my experience, new and uneducated investors like to buy coins that have a low price because they incorrectly feel as though they hold “a lot” of something, and therefore “if it just hits a certain price, I’m rich.”

Because of this, having a large supply may actually help KIN grow for a long time by attracting certain types of investors.