Retirement Social Security

Here’s How Social Security Decides the Size of Your Check

Learn how the SSA calculates your benefit

By Chris Lewis, CEPF , Edited by Laura Hohenstein

Updated Oct. 13, 2026

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Social Security is vital for retirement, yet many don't know how their benefit is calculated. If you're wondering how much you can expect from your monthly check, the Social Security Administration uses a specific formula based on lifetime earnings, claiming age, and other factors.

Knowing this helps you decide when to retire, how long to work, and what to expect from your checks. As you plan for retirement, here's a breakdown of how benefits are determined and how your choices affect the amount you'll receive each month.

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It starts with your highest 35 years of income

Your Social Security benefit is based on your average indexed monthly earnings (AIME). This is calculated by taking your highest 35 years of earnings, adjusting for inflation, and averaging them monthly.

For example, if you worked 35 full years and earned $60,000 annually (adjusted for inflation), your total indexed earnings would be roughly $2.1 million. Then you would divide that by 420 months (35 years multiplied by 12 months), and your AIME would come out to around $5,000.

If you worked fewer than 35 years, SSA fills the missing years with zeroes, in turn lowering your average. Conversely, working more years, especially after low-earning or gap years, can boost your benefits.

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Your AIME is then converted into a benefit amount

Once your AIME is calculated, a formula determines your primary insurance amount (PIA), which is your monthly benefit if claimed at full retirement age (FRA), currently 67 for those born in 1960 or later.

The PIA formula uses bend points, which apply different replacement rates to portions of your AIME, and is rounded to the next lower multiple of $.10 if it is not already a multiple of $.10:

90% of the first $1,286
32% of the amount between $1,286 and $7,749
15% of the amount above $7,749

These bend points update annually. The formula replaces a larger income share for lower earners, and less for higher earners.

Using the earlier example of a $5,000 AIME, here's how the calculation would look:

90% of the first $1,286 = $1,157.40
32% of the next $3,714 (the portion between $1,286 and $5,000) = $1,188.48
Total PIA = $2,345.88

Rounded down to the next lower multiple of $0.10, the retiree's monthly benefit at full retirement age would be $2,345.80 before any cost-of-living or early/late claiming adjustments.

When you claim can impact your benefit

When you claim benefits can be just as important as how much you've earned. You can collect Social Security as early as 62, but if your FRA is 67 and you claim at 62, your monthly benefit will be cut by about 30%.

On the other hand, if you delay benefits past your FRA, you earn delayed retirement credits. Your monthly benefit increases by 8% annually for each year you wait, up to age 70. That means someone with a PIA of $2,345.80 who waits until age 70 to claim would receive about $2,909 per month instead.

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Other factors can reduce or increase your benefit

Several other elements can affect your final benefit amount. If you have fewer than 35 years of work history, each missing year is counted as zero, pulling down your AIME and ultimately your PIA.

If you consistently earned well below the wage base limit (which is $184,500 in 2026), your benefit will also be lower than the maximum. However, most people do not need to max out earnings to get a solid benefit; you just need a consistent, moderate income over time.

Additionally, if you work while receiving Social Security before reaching full retirement age, your benefits might be temporarily reduced. In 2026, if you are under full retirement age and earn more than $24,480, the Social Security Administration will withhold $1 in benefits for every $2 you earn above that limit.

This is called the earnings test limit, and it increases to $65,160 the year you reach full retirement age, before your birthday month. They withhold $1 for every $3 you earn above that limit. These reductions are not permanent; your benefit will be adjusted later to account for the amount that was withheld.

Spousal and survivor benefits follow different rules

Social Security also provides spousal and survivor benefits, which use a different formula than standard retirement benefits.

A spousal benefit can be as much as 50% of the other spouse's primary insurance amount if claimed at full retirement age. The actual amount depends on the age at which the claim is made and the spouse's own work record, and if claimed early, the benefit is reduced. Unlike retirement benefits, spousal benefits do not grow if you delay past full retirement age.

Survivor benefits are paid to the spouse, ex-spouse, child, and sometimes, other dependents of someone who worked and paid Social Security taxes before they died.

It can be up to 100% of the deceased spouse's benefit, depending on the survivor's age and circumstances. In both cases, these benefits are not based on your own earnings history, but on your spouse's, which makes understanding the household benefit structure even more important.

You can review your numbers now to plan better

To find out what your projected benefit looks like, visit ssa.gov/myaccount and create an account. You can view your full earnings record, your estimated retirement benefit at different claiming ages, and identify any missing or low-earning years that could be improved.

Checking this information early and reviewing it regularly gives you more control over your retirement strategy. It also helps catch errors in your work record that could affect your future payments if not corrected in time.

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Bottom line

Your Social Security benefit is based on a specific formula that starts with your top 35 years of earnings, then adjusts that average using a progressive system of bend points. Your final monthly payment also depends on when you choose to claim, with early filing reducing your benefit and delayed filing increasing it.

While you cannot control every factor, understanding how the math works puts you in a better position to make the right moves. The more you know about how your check is calculated, the more you can do to maximize what Social Security provides when you need it most.

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