MSB trading, page-1085

I don't have the calculation but the there is a tool called Fib (fibonacci) retracement.
https://www.tradingview.com/wiki/Fib_Retracement

The main way to use it is to make a start point at a high and then add an end point at the lowest point after a the high. Some choose to set a sell points at each level that the tool gives you.

The other way is to do the opposite but and is just a quick way to gauge what is happening to the price.

Never use any single method on its own.

It is also better researching it further. I prefer not lecture (for lack of a better word) people on how to trade a stock.

Good luck and happy profits.