Fewer than half of American wage earners are saving adequately for a comfortable retirement. This is serious news for women because women live longer than men (about seven years); save less than men (about half); start saving later than men and make more conservative (lower yield) investments.

Ideally, you should begin saving for retirement in your twenties. The longer you save, the easier it is to meet retirement income goals.

This question is difficult because the answer depends on your income and assets, your goals for retirement, and many other factors. Ideally, you should begin saving for retirement in your 20s. More time to save maximizes your chances of having the kind of retirement lifestyle you want.

If you're in your 40s or older and haven't saved much (or anything) yet, you may face a challenge in building the retirement fund you need. The shorter your time frame, the less room you have for error. But don't panic--it's never too late to start saving. You may still be able to secure a comfortable retirement for yourself, but you may have to make some tough choices to do so. Here are a few tips if you're getting a late start:

• Save as much as possible: The more you save, the more you'll have when you retire. Try to maximize your contributions to IRAs, 401(k)s, and other tax-advantaged vehicles. Then supplement your retirement fund with mutual funds, savings accounts, and other investments.
• Cut current expenses: Chances are, not all of your expenses are absolutely essential. If you can wipe out or trim certain expenses, such as videos, expensive coffees, and daily lunches out, you'll free up more money to invest for retirement.
• Invest more aggressively: This can help you build a large retirement fund in a short time. Certain stocks and mutual funds may enable your savings to grow more rapidly. The tradeoff: These investments will expose you to greater volatility.
• Delay retirement: You may have no choice but to delay your retirement until after age 65. This strategy will buy you more time to build your nest egg. Plus, the more years you work, the fewer years of retirement you'll have to fund.
• Rethink your retirement goals: Set more realistic goals for your retirement (no beach house on the Riviera, for example). That way, you won't need as much money to fund your retirement.

If you fear you're getting too late a start, or you're not sure where to start, consult a financial planner. He or she can help you map out a plan to bridge the gap between where you are now and where you need to be when you retire.