Perhaps you've counted all your beans and think you have enough to retire ... just barely enough. What can you do to build in a margin of error -- something that will protect your retirement against unpleasant surprises? That's easy: Work longer.

I know it's not a popular suggestion, but it's a powerful one. Working just a few more years can put your retirement on a much stronger foundation. Here are four reasons to wait just a few more years to retire.

1. A bigger nest egg
First of all, your savings get a few more years to grow. For example, $100,000 permitted to compound three more years at 8% a year will turn into $126,000. Plus, you'll be adding to those savings as well, which could push that nest egg to $140,000 or higher. On top of that, the longer you wait to retire, the fewer years of retirement your portfolio will have to sustain. Thus, you've increased your retirement income and decreased the chances that you'll outlive your portfolio.

2. A higher Social Security check
The calculation of Social Security benefits considers your earnings history and the age at which you choose to begin receiving checks. (Yes, you do have a choice.) As a hypothetical example, a 62-year-old who earned $60,000 last year and decides to receive Social Security retirement benefits this year could get approximately $13,900 annually (based on the "Quick" benefits calculator at However, if that person waited until "full retirement" age (66 years old, for someone born in 1948), the annual benefit would jump to almost $19,600. Postponing Social Security until age 70 for this retiree would increase the annual benefit to approximately $27,200.

Now, there are many valid arguments for getting your hands on that money as soon as you turn 62 (as 60% of beneficiaries do). However, because work-related income before full retirement age reduces benefits, and because benefits can be taxed, waiting to receive Social Security might be your best move.

3. A bigger pension check
This same principle applies if your employer offers a defined-benefit plan. How much you'll receive depends on the plan's formula. For example, it might stipulate that for each year you've worked for the company, you'll receive 1.5% of the average of the final three years' salaries. If you worked for a company for 15 years and your three-year salary average was $60,000, you'd receive $13,500 a year. However, if that same person waited three years and earned 3% annual raises along the way, the annual pension benefit would jump to around $17,200.

4. Help with the doctor bills
The average age of retirement these days is 63, and the age of Medicare eligibility is 65. That's a two-year gap in health insurance coverage that early retirees must cover themselves -- not an inexpensive prospect. However, waiting until age 65 and joining Medicare should reduce the out-of-pocket health-care costs for most retirees.

The whole is greater with bigger sums
Add it all together -- more savings, higher benefits -- and working just a few more years can greatly improve the rest of your life.

Need help objective, expert help deciding when you should retire? We Fools like the fee-only planners of the Garrett Planning Network, who are now offering a limited-time 10% discount to Motley Fool readers. Just click on your state on the Locate an Advisor map, and look for the Fool logo for participating advisors.