Each year, many Americans receive a letter that results in a variety of emotions from excitement to great anxiety. It is a statement from the Social Security Administration with their projection of the monthly benefits the recipient will receive in retirement.

These projections are based on several variables and Social Security assumptions including that earning will continue at current levels, that its benefits structure will stay much the same as currently exists and, above all, that the individual continues working until past age 65.

That’s right—a number of years ago the federal government moved the goal post back on when old is and, therefore, when and how much in benefits will be given. Anyone born after 1937 will find that they cannot collect full benefits at 65 but must work until age 66 or 67. The earliest that a worker can begin collecting retirement benefits is age 62.

But workers who opt to begin taking retirement pay at age 62 receive far lower monthly payments than they would if they worked until what Social Security now calls “normal retirement age.”

For example, workers born in 1960 or later must work until age 67. If they retire at age 62, their monthly benefit will be about 30 percent lower than if they continued working for another five years. On the other hand, workers born after 1942 can increase their benefit by 8 percent for each year that they work past their “normal retirement age.”

Just how much would a worker give up by retiring at 62 or gain by working until age 70? The Social Security Administration Web site (www.ssa.gov/planners/calculators.htm) offers three interactive calculators to estimate future benefits.

The simplest one calls for the worker’s date of birth and current income. With that information, it gives a rough estimate of benefits for early, regular or delayed retirement. For example, the site projects that a 50-year-old earning $50,000 will have an estimated monthly benefit amount of $1,096.00 if retiring at age 62 years 1 month, $1,514.00 if retiring at age 66 (an increase of 38 percent), and $2,046.00 if retiring at age 70 (an increase in benefits of more than 35 percent over the benefits at age 66 and more than 86 percent by waiting eight years to retire).

The Web program also provides estimates of benefits figuring in cost-of-living adjustments and increases in the national average wage index, a calculation of how long one would have to live to be better off delaying retirement, and a statistical table for life expectancy.

For a more exact estimate, use the calculator which asks for a year-by-year earning history. This calculator uses the current year’s income as the figure for future years from now to retirement. These two calculators can be operated online with results in moments.

The most detailed calculator is a program that can be downloaded from the Social Security Administration Web site. It allows the user to provide future annual income. This last program would be most useful for workers who are contemplating large reductions in pay or who are thinking of stopping work for a period, perhaps to deal with family responsibilities.

These calculators can also tell workers what benefits they can expect if they are disabled before retirement as well as what benefits would be paid to their survivors in the event of their death.

All these calculations are based on present formulas. The Web site warns that if no changes are made in Social Security funding within 15 years, benefits paid out will begin to exceed contributions paid in.

Individual workers can use the benefits calculator to look at what they can expect and then decide to change course, to earn more, to work longer or retire earlier.