Imagine you are 25yrs old and earning $50,000 per year. You think smartly that you would like to do some long-term retirement planning and begin to brainstorm with yourself as to what you should do. You decide that having $50,000 per year in retirement would be a good and that you expect to work until 65 and plan on being retired for 30 years.

How much do you expect to reasonably save as a percentage of your salary?

And what interest rate do you need to achieve during your working years and retirement years such that your plan will work.