First, 8% compounded monthly is not realistic long term return. A more realistic number for money invested in the stock market will be 6-7% , 8-10% was a figure that was previously used As for inflation, you can assume historical number of 2-3%, so if you want to figure out what your money would be worth in current dollars simply deduct the inflation rate from your investment returns so 8-3 = 5% investment growth. You have discovered on your own the power of compounding. You can significantly increase your retirement money by continuing to contribute annual to your saving.

A good financier should look what would be the best way to calculate of their loan using calculator. With these regard I can show you some basic step on how to do it.

I'm using this calculator:

http://www.moneychimp.com/calculator/compound_interest_calculator.htm

I'm 25 and I have $50k saved up. Apparently if I put it into a compound interest savings account at 8% (compounded monthly) without even adding any extra money, I will have about $1.2 million by the time I'm 65. I have some questions on this:

Is 8% realistic? How much would that be after inflation and taxes? Should I invest that $50k on this or something else?