According to Kemper's formula: A person need a total of 0.06624605 BTC in order to guarantee wealth worth $1 million.
There is no such guarantee and for sure it's not going to be a formula to do so.
In case somebody is interested in the details of the formula, here is it, pretty old stuff (in bitcoin time)
https://investory-video.com/blog/earn-bitcoin-crypto-millionaireIt basically estimates the whole coinmarketcap of Bitcoin is going to be the same as the global wealth and then divide it to find how much would a million be in BTC.