What will your Social Security benefit be when you retire? Knowing how much you will receive from Social Security can help with your retirement planning. Two-thirds of Americans rely on Social Security for most of their income in retirement, and one third rely on it for virtually all (90 percent or more) of their retirement income.

The Social Security Administration cannot tell you exactly what you will get.  But, it has a calculator that will provide you an estimate. What you receive depends on the average of your top 35 earnings years, as well as on the age at which you choose to claim Social Security.

You can sign up to get benefits before the full retirement age (age 66 today, i.e. for those born between 1943 and 1954, and rising to age 67 for those born in 1960 or later). But your benefit will be reduced by around 6 percent for each year you retire prior to your full retirement age — up to a 25 percent reduction if you retire at age 62, the earliest possible age you can claim benefits. If you wait until after your full retirement age to claim benefits, your benefit is increased by 8 percent per year — up to a 24 percent increase if you wait till age 70.

Your benefits will be protected against inflation by cost-of-living increases. And, of course, if Congress changes the Social Security Act, that could affect your benefits as well.  In January 2015, the average estimated monthly benefit for a retired worker was just over $1300 and just over $2100 for a retired couple.

To qualify for benefits, you need at least 40 credits of earnings, i.e. 10 years of either working four quarters or paying enough into Social Security during the year to satisfy the four-quarters requirement. To understand how credits are calculated, click here. Or, you might qualify based on the earnings record of a current or divorced spouse (if the marriage lasted 10 years or longer).