Your Social Security checks help cover your living expenses in retirement, easing the strain on your personal savings. But if you want to maximize your benefits, you need to understand how they're calculated.

There are two key factors that determine how much money you'll get every month: your average monthly earnings during your 35 highest-earning years, and the age you begin taking benefits. You may not have a ton of control over the first one, but the second one is entirely your decision. Here's what you need to know in order to make the right choice.

Social Security card with $100 bill

Image source: Getty Images.

How your age affects your Social Security benefits

You can begin collecting Social Security as early as 62, but if you want your full scheduled benefit, you must wait until your full retirement age (FRA). This is 66 or 67, depending on the year you were born. If you start before this, the Social Security Administration will reduce your checks to account for the extra months you're receiving benefits according to this schedule:

  1. If you are 36 months or less below your FRA, multiply 5/9 of 1% (0.0056) times the number of months until your FRA. Multiply this percentage by your scheduled benefit at FRA, and then subtract this amount from your scheduled benefit at FRA.
  2. If you are starting benefits more than 36 months before your FRA, multiply 5/9 of 1% (0.0056) times 36, and add 5/12 of 1% (0.0042) times the number of additional months you are below FRA. Multiply this percentage by your scheduled benefit at FRA, and then subtract this from your scheduled benefit at FRA.

So, if you are claiming benefits 40 months below your FRA, for example, you would multiply 5/9 of 1% (0.0056) times 36 to get 20%, and then multiply 5/12 of 1% (0.0042) times 4 for the additional four months you are below your FRA, which would get you 1.7%. Add the two together and you get 21.7%. Then, you'd multiply this by your scheduled Social Security benefit at FRA -- let's say $1,000 for this example -- and you'd get $217. Subtract this from $1,000 and you'd get a monthly benefit of $783 per check if you began claiming benefits 40 months below your FRA.

If you start Social Security as soon as you're eligible at 62, you'll receive only 70% or 75% of your scheduled benefit per check, depending on your FRA. You can also delay benefits past your FRA, and your checks will increase by 2/3 of 1% (0.0067) for every month you delay until you reach the maximum benefit at 70. This is 124% or 132% of your scheduled benefit per check, again depending on your FRA.

How to choose the right age to start Social Security

Choosing the right age to begin Social Security is essential to maximizing your lifetime benefits, but later isn't always better. Consider the following example. You're entitled to the average Social Security benefit of $1,467 if you wait to claim until your FRA of 67, but you're not sure if you should start then. Claim at 62 when you'd only get $1,027 per check, or wait until 70 when you'd get $1,819 per check. You expect to live to 87, so you create the following chart to determine how much you'd receive in lifetime benefits if you started at each age. All numbers indicate how much you'd have received in total Social Security benefits by the end of that year.


Age 62 ($1,027 per check)

Age 67 ($1,467 per check)

Age 70 ($1,819 per check)









































































































If you actually live until 87, waiting until 70 to start Social Security would give you the most benefits during your lifetime. But if you live only to 81, starting at your FRA would give you the best deal. If you live only to 77, you'd have been better off starting right away at 62.

The tricky part is you never know how long you're going to live, so you'll never know if you're choosing the right starting age. But you can give yourself the best shot at the most benefits by choosing your starting age based on your estimated life expectancy. Create a My Social Security account to estimate your benefits at each of the three ages listed in the table. You can use the calculations listed above to determine how much you'd get if you began Social Security at an age other than 62, FRA, or 70. Then, use this information to create a chart like the one above to help determine the ideal age for you to start.

Of course, even if you'd like to wait to begin benefits, you may not be able to if you truly need your checks to get by. In that case, try to delay benefits as long as you can. Even waiting a month or two can make a difference in how much you receive over your lifetime.