That ancient quote is a great reminder how important it is to start planning for your retirement. Whether we choose to acknowledge it or not, retirement is creeping up on us. Even for those who have just started their career, retirement planning is essential to providing a secure future for themselves and their loved ones. But that doesn't mean we're defenseless against time. In fact, with the proper planning, life after work can be the most rewarding years of your life.

One of the most basic ways to begin planning for retirement is determining your post-work income. Post-work income is the amount of money you'll need to live comfortably at current income levels, after you've retired. That means having enough money to live comfortably without worrying about running out. It also means making sure you have enough extra to do the things you've always wanted to, like travel, or just plain relax!

Meeting with a financial professional and determining your post-work income is fairly painless. But not many Americans have done it. According to the 2005 Retirement Confidence Survey (RCS), released annually by the Employee Benefits Research Institute, less than half have tried to calculate needed savings for their golden years. In fact, only 4 in 10 workers say they have tried to calculate how much they need to accumulate for retirement.

So here's a quick rundown of determining what you'll need to save for retirement. Your post-retirement income heavily depends on the age you wish to retire and how much money per-year you wish to spend. Generally, you want to have between 75% and 95% of your pre-retirement income available to you, per year. This way, you won't be forced to deal with a drastic drop-off in the way you live. Many people grow accustomed to living on a certain income, and it's important to stay consistent after retirement. People are living longer too, so you'll also want to take that into account, along with inflation. In general, it's been said that in order to preserve your retirement assets, you'll want to take out 6% or less of them per year.

Here's a quick and easy example of how to determine what you'll need to save to be in the ballpark: Say you retire at age 65 and decide you'll need 30 years of dependable income, at an average of $55,000 a year (assuming you can live comfortably on that amount). That means, you'll need to save approximately $1,650,000 to make sure you have enough to retire. And that's without taking inflation, medical costs, travel, and any other unexpected expenses into consideration.

Getting a rough idea of a number is a good way to light a fire under your retirement plan. Often people believe they are saving enough, when the reality is, they'll fall short of what is needed. By determining a rough estimate, you can then work with a financial professional to nail down an exact number. The sooner you get started saving, the easier it is on your future.

Of those 4 in 10 who have calculated, one-third has done so with the help of a financial professional. Unfortunately, a whopping 10 percent say they simply guessed how much they will need in retirement! While something can be said for "doing it yourself," or if you choose, just guessing (we don't recommend that!) most post-retirement income estimates need to be tested for real-world accuracy by financial professionals.

For instance, you may come up with a number that seems sufficient, but with the help of an expert, your number can be put through a series of scenarios to see if it holds up under certain real-world situations. By running it through a series of tests, professionals can determine what possible risks and warning signs may come up. Say, for instance, if you or a spouse were put in a long-term care facility at some point during retirement, your advisor can look at your determined number and see if it will hold up under the strain.

By determining the exact amount of post-retirement income you'll need, you've taken the first step towards saving for your retirement. Once you get that out of the way, you've begun down the path of securing your future. Asking for help can be crucial, because a professional can tell you if your number will hold up in case of emergencies or other unexpected events. Meeting with a professional and determining how much you need to save is the first step towards determining future goals for retirement. It will wake you up to the real number you need to reach. Best of all, it's painless, and you'll be glad you did it.