Are you on track for a happy, financially secure retirement? Here are two quick "rules of thumb" you can use. When you are ready to retire your nest egg should be at least 10 times your current annual income. (Take your current annual income and add a zero -- that's your minimum target nest egg balance to begin a comfortable retirement). By the time you reach age 40, the balance in your nest egg should roughly equal your annual income at age 40. (If your annual gross income is $60,000, you should have at least that amount in your retirement account by age 40). But the best way to determine how much you need to retire is by using a financial calculator. This is a great desktop tool for quick calculations to make sure you are on track. If you don't know where you're going, you'll never get there.