Good health and employer willing, you can also choose when to retire. "Retiring later is a very powerful lever," says Munnell. "It completely changes the arithmetic." How?
It raises your monthly Social Security benefits. The maximum benefit at 62, for instance, is a tad over $1,800 a month. If you hold off claiming Social Security until age 70, your monthly benefit jumps about 75 percent, to almost $3,200. And because Social Security is one of the few sources of retirement income that rises with inflation, starting off with the greatest benefit you can get is truly the gift that keeps on giving.
It allows your retirement savings to accumulate for more years, possibly helping you regain lost ground.
It shaves the number of years you'll need to live off your savings. After all, just because you work longer doesn't guarantee you'll live longer.
Finally, you can choose to live on less income than you may have initially aimed for. Planners often assume you'll need a retirement income equal to 70 to 80 percent of your salary to maintain your pre-retirement standard of living. You don't want to condemn your older self to destitution, but Get a Life author Warner believes you can live with less if you adopt the right perspective.
Warner came to this comforting conclusion after talking with hundreds of retirees. He cites a character in his book, a golf enthusiast named Howard who beats greens fees by volunteering as a country club course marshal in exchange for free golf. Another retiree, Ed, gave much of his savings away when he retired. Why? He thought his kids needed it more, and his hobby — archaeology — didn't cost much. Now in his late 70s, Ed describes himself as "a penniless desert rat," living frugally but happily near an archaeological dig in New Mexico.
The point is that the real answer to the "how much you'll need" question may include less money than you think and more of the things that are hard to count. Sure, aim high in your financial plan, says Warner, but don't forget that strong relationships with friends and family, hobbies that allow you to make the world better, and activities that keep you moving and learning will contribute more to your happiness than a pot of gold. "If you look back at your 20s or 30s and consider the most important things that happened to you, it would be a long time before you got around to talking about how much money you made," he says. "Why should that be different when you're in your 70s or 80s? You'll do much better planning for retirement if you recognize that it's not all about money."
Kathy Kristof is a financial journalist and the author of Investing 101.
You may also like: Retirement planning in a down market.