An early retirement means more time to relax and enjoy the activities you love. But if you were counting on large Social Security checks to cover most of your living expenses in your later years, you could be in for a surprise. Retiring early can have some unintended consequences for your Social Security benefits that end up costing you thousands of dollars over your lifetime.

How early retirement can affect Social Security benefits

Your Social Security benefit is based on your average monthly income during the 35 highest-earning years of your life. But if you retire before you've worked for 35 years, the Social Security Administration (SSA) will add zeros to your calculation, bringing down your average and reducing your monthly checks. And if you've worked for less than 10 years, you won't be eligible for Social Security at all.

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If retiring early also means starting Social Security early, you could end up with even less money per check. If you want the full monthly benefit you're entitled to, you must wait to claim until you reach your full retirement age -- 66 or 67, depending on the year you were born. The SSA reduces your checks for every month you receive benefits before your full retirement age. If you start as soon as you're eligible at 62, you'll only receive 70% of your scheduled benefit per check if your full retirement age is 67, or 75% if your full retirement age is 66. Conversely, you can delay benefits past your full retirement age: Your checks will grow until you reach the maximum benefit at 70. This is 124% of your scheduled benefit for those with a full retirement age of 67 and 132% for those with a full retirement age of 66.

Starting benefits early could result in a lower lifetime Social Security benefit than if you'd waited until your full retirement age or 70 to begin claiming, but it all depends on how long you expect to live. If you don't anticipate having a long life, you'll get more from Social Security by starting early than you would by waiting. You can calculate your estimated Social Security benefit at different ages by creating a my Social Security account. Multiply these amounts by 12 to get your estimated annual benefits at these ages and then multiply this by the number of years you expect to receive benefits to figure out your lifetime benefit.

For example, if you expect to get $1,000 per month if you start claiming at your full retirement age and you expect to collect benefits for 20 years, you'd multiply $1,000 by 12 to get $12,000 per year and multiply this by 20 to get a $240,000 estimated lifetime benefit. Use this data to determine which age offers you the most benefits.

Strategies to delay Social Security benefits

If you don't want your early retirement to derail your Social Security benefits, make some adjustments to your retirement plan. Consider delaying your retirement a year or two, or working part-time for a couple of years if you don't have 35 years of work history under your belt. This will ensure there aren't any zeros weighing down your average monthly income that's used to calculate your benefits.

If you don't need Social Security to cover your living expenses, consider delaying benefits until your full retirement age or 70 so you can get a larger amount per check. These checks will then cover a larger portion of your living expenses later in retirement, easing the burden on your personal retirement savings.

Married couples may want to consider having the lower-earning spouse start Social Security at 62. Their checks can help hold them over while the higher-earning spouse delays benefits until full retirement age or 70, when they're entitled to larger checks. Then, when they sign up for benefits, their spouse can switch over to a spousal benefit if that is larger than the benefit they're entitled to based on their own work record.

It's possible that your early retirement may not affect your Social Security benefits at all if you already have 35 years of work experience under your belt and you already know when you want to start benefits and approximately how much you'll get. But if you haven't given these things any thought, now's the time to do so.