Calculation to determine how much to save to reach goals?

[Brooklyn Owen]

I finished reading J Scott's and Dave Meyer's new book, Real Estate by the Numbers. J Scott is a great author and the book was super helpful. But, it is desperately missing an index and makes it incredibly difficult to lookup specific calculations I need to make. Does anyone know where in the book or simply what calculation I need to use to determine how much I should be investing each year to reach my financial goals?