The Social Security benefits formula is used by the Social Security Administration, or SSA, to determine the initial Social Security formula of retirees, their spouses, and other beneficiaries.
Unfortunately, many don't understand how this formula works. Thankfully, it's not too difficult to figure out as long as you're comfortable with basic arithmetic. Below, we'll break it down step by step so you can better estimate how much money you'll get from the program.
What is the Social Security benefits formula?
The Social Security benefits formula is what the government uses to determine your primary insurance amount (PIA). That's the benefit you're entitled to if you sign up at your full retirement age (FRA). This is 67 for anyone born in 1960 or later.
Before the government can use the benefits formula, it must calculate your average indexed monthly earnings (AIME). This is your average monthly earnings over your 35 highest-earning years, adjusted for inflation.
Once the government knows your AIME, it plugs it into the Social Security benefits formula in effect during the year you turned 62. The result is your PIA. But that's not always the same as your monthly benefit.
Some people choose to apply for Social Security before or after their FRA. If you claim early, you can receive benefits as soon as you turn 62. You'll get more checks this way, but each one will be smaller. You can also delay benefits, and your checks will grow a little each month until you reach your maximum benefit at age 70.
In both of these cases, the government runs an additional calculation to determine how to adjust your PIA to determine your final monthly benefit.
Social Security benefits formula 2025
The Social Security formula for the year 2026 -- which applies to anyone born in 1964 -- is as follows:
- Multiply the first $1,286 of your AIME by 90%.
- Multiply any amount between $1,286 and $7,749 by 32%.
- Multiply any amount over $7,749 by 15%.
- Add the results from the three steps above and round to the next lowest $0.10.
So, for example, if your AIME was $3,000, you would do the following:
- Multiply the first $1,286 by 90%, giving you $1,157.40.
- Multiply the remaining $1,714 by 32%, giving you $548.48.
- Multiply any amount over $7,749 (in this case $0) by 15%, giving you $0.00.
- Add the results from the three steps above, which gives you $1,705.88. Round this down to $1,705.80.
In the formula above, $1,286 and $7,749 are known as the bend points. These are the only parts of the Social Security benefits formula that change from one year to the next, unless Congress passes specific legislation changing the program.
How to calculate your Social Security benefits
If you simply want to know how large your Social Security checks will be if you sign up at a certain age, you can figure this out by creating a my Social Security account. But if you want to understand how the government arrived at this number, you can duplicate its work by taking the following steps:
1. Determine your wages for each year you've worked
The federal government keeps track of how much money you've paid in Social Security taxes for each year in your earnings record. You can view this in your my Social Security account.
For most people, their actual income and the income they've paid Social Security taxes on are the same. But this isn't always the case with high earners. In 2026, for example, you only pay Social Security taxes on the first $184,500 you earn. This ceiling rises each year. If you earn $200,000 this year and your earnings record only shows $184,500 for 2026, that's correct. Your earnings record only reflects the income you paid Social Security payroll taxes on.
2. Adjust your wages for each year for inflation
The government uses the Average Wage Index (AWI) to adjust your wages for inflation so it can accurately pick out the years you've earned the most. This is used to calculate index factors for each year of your earnings.
Here's how this works. Let's say that you first become eligible for Social Security in 2026, and that you earned $50,000 in the year 2003. According to the SSA, the index factor for 2003 is about 2.0504. Multiplying this by your earnings for that year gives adjusted earnings of about $102,520. This is the number that will be used in the Social Security benefits formula.
The Social Security Administration keeps lists of all the indexing factors for all years. You just have to enter the year you turn 62, and it will give you the index factors to use.
3. Calculate your AIME
After you've adjusted your income for inflation, total up the income from your 35 highest-earning years. If you didn't earn income in at least 35 years, then total your income for all the years you've worked.
Next, divide this total by 420 -- the number of months in 35 years -- which will give you your AIME. It may not be as high as you expect if you worked fewer than 35 years because you'll have some zero-income years factored into your calculation.
4. Apply the Social Security benefits formula
Once you know your AIME, you can plug it into the Social Security retirement benefits formula as outlined above.
Be sure to remember to choose the correct formula for your age. You should use the one that was in effect in the year you turned 62, regardless of whether you signed up for benefits at that age.
The results you get from this step will give you your PIA. If you choose to sign up at your FRA, that's also how much you'll get for a benefit. But if you sign up before or after your FRA, there are a few extra steps to calculating your monthly benefit.
5. Adjust your PIA up or down as necessary
To do this step, you need to know what your FRA is. Here's a table to help you figure that out:
If you claim Social Security early, the government reduces your checks by:
- 5/9 of 1% per month up to 36 months
- 5/12 of 1% for each additional month if you claim more than 36 months early
For example, if your FRA is 67 and you claimed at 62, you'd lose 5/9 of 1% from your checks for each of the first 36 months you claimed early. So you'd multiply (((5/9) x 0.01) x 36) x 100, and you'd get a 20% reduction.
Then, you have to add a further 5/12 of 1% monthly deduction for claiming two additional years' worth of checks between 62 and 63. So you'd take (((5/12) x 0.01) x 24) x 100, and you'd get an additional 5% decrease. Added together, the two steps above result in 30% smaller checks for claiming at 62 as opposed to waiting until 67.
For those who choose to delay benefits past their FRA, the process is pretty similar. You add 2/3 of 1% per month for every month you delay past your FRA. However, this only continues until you turn 70. After that, your benefit won't grow anymore.
6. Subtract your Medicare Part B premiums if necessary
The five steps above will tell you the kind of benefit you're entitled to based on your work history and claiming age, but that's not always the same as your take-home benefit. Seniors on Medicare have their Part B premiums automatically deducted from their Social Security checks.
Of course, if you're not on Medicare yet, you won't have to worry about this until you sign up for it.
7. Round your benefit amount down to the nearest dollar
The final step in calculating your take-home Social Security benefit is to round your answer from Step 6 down to the nearest dollar. Even if your result from the previous step was $1,680.99, you'd still round down to $1,680 rather than rounding up to $1,681.
A quick word on cost-of-living adjustments (COLAs)
Every year, the government administers a cost-of-living adjustment (COLA) to help seniors' Social Security checks keep up with inflation. But it doesn't add the COLA to your take-home check. It adds it to your PIA.
If you want to calculate the size of your checks for next year, look at your PIA for the current year and add the COLA. For example, the 2026 COLA was 2.8%, so you'd take your 2025 PIA and multiply it by 1.028 to get your 2026 PIA. Then you proceed with Steps 5 to 7 above to determine your new take-home benefit for the next year.
Why is the Social Security benefits formula important?
Once you understand how the government calculates your Social Security benefit, you can use this information to boost your own benefit. For example, if you didn't know that the government bases your benefit on your 35 highest-earning years, you might have retired before you worked that long. That would have resulted in zero-income years being included in your benefit calculation.
Understanding how your FRA plays into your benefit calculation can also help you choose the best time to sign up. This depends on your life expectancy and financial circumstances.
You can use the steps above to calculate your benefit at various claiming ages. Then multiply each of these monthly benefits by 12 to get your estimated annual benefit. You then multiply this figure by the number of years you expect to claim to get your estimated lifetime benefit. For example, if you expect a $2,000 monthly check at your FRA of 67 and believe you'll live to 87, you'd have an estimated lifetime benefit of $480,000.
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The bottom line
The Social Security benefits formula might seem complicated, but it's not too difficult once you break it down. You may not be able to precisely calculate your benefit if you're too young for Social Security, but keeping these guidelines in mind can help you squeeze the most money possible out of the program.
Social Security Benefit Formula FAQ
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