Quick Answer
Quick Answer: The calculator estimates your benefit in three steps. It converts your earnings into Average Indexed Monthly Earnings (AIME), runs AIME through the progressive bend-point formula (90% / 32% / 15%) to get your Primary Insurance Amount (PIA) -- your benefit at full retirement age -- and then adjusts the PIA for the age you claim. For a worker eligible in 2026 earning $80,000 over 35 years, the engine returns an AIME of $4,333, a PIA of $2,132.40 per month at full retirement age, $1,492.68 if claimed at 62, and $2,644.18 if claimed at 70. This page shows the complete math behind every number.
Key Takeaways
- The engine uses four core inputs -- birth year, current earnings, years worked, and claim age -- plus an optional life expectancy for the lifetime projection
- Benefits are built from AIME → PIA → announced COLAs → claim-age adjustment, in that order
- The bend points ($1,286 and $7,749 for 2026 eligibility) are locked the year you turn 62 and never change
- Claiming at 62 permanently cuts an FRA-67 benefit to 70% of PIA; waiting to 70 raises it to 124%
- Figures are a simplified, present-day estimate -- the tool does not model your exact 35-year earnings history, spousal or survivor benefits, taxation, or future COLA
Social Security Benefits in Plain English
Your Social Security retirement benefit is not a flat percentage of your salary. The Social Security Administration (SSA) builds it from your lifetime earnings using a progressive formula that replaces a much larger share of income for lower earners than for higher earners. Our calculator follows the same shape as that official formula, with one simplification noted below.
The calculator walks the same steps every time:
- Estimate your Average Indexed Monthly Earnings (AIME) -- a monthly average of your career earnings, capped at the annual Social Security wage base.
- Apply the bend-point formula to AIME to get your Primary Insurance Amount (PIA), the benefit you would receive at your full retirement age (FRA).
- Add the cost-of-living adjustments (COLAs) SSA has already announced since the year you turned 62.
- Adjust the PIA down if you claim before FRA, or up if you delay past FRA.
- Optionally project total lifetime benefits by multiplying the monthly amount by the months you are expected to collect.
The key idea is the bend-point formula. Like federal tax brackets, it is progressive: the first slice of your AIME is credited at 90%, the middle slice at 32%, and the top slice at only 15%. That is why a worker who earns twice as much does not get twice the benefit. The SSA Primary Insurance Amount page(opens in new tab) is the authoritative reference for this formula.
One honest simplification: SSA computes AIME from your highest 35 years of wage-indexed earnings. Because a calculator cannot see your full earnings record, our engine approximates AIME from your current earnings and years worked. The result is a solid ballpark, not your official figure -- see the scope notes in Section 8.
The Formula
Here are the exact rules used by our Social Security Calculator. Let S be current earnings, Y years worked, and W the Social Security wage base for your eligibility year ($184,500 for 2026).
Step 1 — AIME
AIME = floor( min(0.65 × S, W) × min(Y, 35) ÷ 420 )
Current earnings are scaled by a 0.65 career-average factor, that career average is capped at the wage base, then spread over up to 35 years and divided by 420 (35 years × 12 months). The result is floored to a whole dollar. This is the calculator's simplified stand-in for SSA's exact 35-year indexed-earnings average. The cap applies to the career average, not to your current salary. A worker whose average is at the cap is modeled as having earned the taxable maximum every year, which is what SSA's maximum benefit assumes. For 2026 eligibility that happens once current earnings reach about $283,846 (the $184,500 wage base ÷ 0.65).
Step 2 — PIA (the bend-point formula)
Let BP1 and BP2 be your eligibility year's bend points ($1,286 and $7,749 for 2026). The PIA is a three-tier weighted sum, rounded down to the nearest $0.10 per SSA convention:
PIA = 0.90 × min(AIME, BP1)
+ 0.32 × (min(AIME, BP2) − BP1) if AIME > BP1
+ 0.15 × (AIME − BP2) if AIME > BP2
Step 2b — Cost-of-living adjustments
From the December of the year you turn 62, your PIA receives every COLA SSA announces, whether or not you have claimed. After each one the PIA is rounded down to the nearest $0.10 again. The engine applies the COLAs announced so far, through the 2.8% COLA for 2026 (effective December 2025), and no future ones:
PIA′ = PIA × (1 + COLA1) × (1 + COLA2) × … (each step rounded down to $0.10)
If you turn 62 in 2026 or later, no COLA has been announced for you yet, so PIA′ = PIA and the result reads in 2026 dollars. The calculator shows which COLAs it applied under your results.
Step 3 — Claim-age adjustment
The PIA is your benefit at full retirement age. Claim earlier and it is reduced; delay and it grows. Let the difference between your claim age and FRA be measured in months:
early: factor = 1 − [ min(monthsEarly, 36) × (5/9)% + max(monthsEarly − 36, 0) × (5/12)% ]
delayed: factor = 1 + monthsDelayed × (2/3)% (capped at age 70)
benefit = PIA′ × factor
Your full retirement age depends only on your birth year:
| Birth Year | Full Retirement Age (FRA) |
|---|---|
| 1954 or earlier | 66 years |
| 1955 | 66 years, 2 months |
| 1956 | 66 years, 4 months |
| 1957 | 66 years, 6 months |
| 1958 | 66 years, 8 months |
| 1959 | 66 years, 10 months |
| 1960 or later | 67 years |
Variable Definitions
| Variable | Meaning | Units / How to Enter | Example (elig. 2026, $80,000, 35 yrs, claim 67) |
|---|---|---|---|
| birthYear | Sets your eligibility year (birth year + 62), which locks the bend points, and your FRA | Integer, 1943 – 2004 | 1964 |
| S (currentEarnings) | Current annual earnings; 65% of it is the career average, which is capped at the wage base | USD, 0 – 1,000,000 | $80,000 |
| Y (yearsWorked) | Years of earnings, capped at 35 for AIME | Integer, 0 – 50 (default 35) | 35 |
| claimAge | Age you start benefits; drives the PIA adjustment | Integer, 62 – 70 | 67 |
| lifeExpectancy | Drives the optional lifetime-benefit projection | Integer, 62 – 120 (default 85) | 85 |
Valid Input Ranges
Our calculation engine accepts a birth year from 1943 to 2004, current earnings from $0 to $1,000,000, years worked from 0 to 50, a claim age from 62 to 70, and a life expectancy from 62 to 120. These bounds match the engine exactly.
Worked Example: $80,000 Earner, Eligible in 2026, Claiming at 67
This section walks through every step for a worker born in 1964 (so they turn 62 -- become eligible -- in 2026), earning $80,000 a year over a 35-year career, claiming at their full retirement age of 67. You can follow along and verify the result against our Social Security Calculator. The 2026 bend points used below are $1,286 and $7,749.
Step 1: Average Indexed Monthly Earnings (AIME)
- Career-average earnings = $80,000 × 0.65 = $52,000
- That career average ($52,000, from the $80,000 salary) is below the $184,500 wage base, so nothing is capped
- Over 35 years = $52,000 × 35 = $1,820,000
- AIME = floor($1,820,000 ÷ 420) = floor($4,333.33) = $4,333
Step 2: Primary Insurance Amount (PIA)
AIME of $4,333 clears the first bend point ($1,286) but not the second ($7,749), so only the first two tiers apply.
- Tier 1: 90% × $1,286 = $1,157.40
- Tier 2: 32% × ($4,333 − $1,286) = 32% × $3,047 = $975.04
- Tier 3: AIME is below $7,749, so $0
- Sum = $1,157.40 + $975.04 = $2,132.44, rounded down to the nearest $0.10
- PIA = $2,132.40 per month (the benefit at full retirement age)
- COLAs: this worker turns 62 in 2026, and SSA has not yet announced a COLA for December 2026, so none applies and the PIA stays $2,132.40
Step 3: Claim-Age Adjustment
- Birth year 1964 gives an FRA of 67, and the claim age is also 67
- Claim age equals FRA, so the adjustment factor is exactly 1.0
- Monthly benefit = $2,132.40 × 1.0 = $2,132.40
Step 4: Lifetime Projection
- Years collecting = life expectancy 85 − claim age 67 = 18 years
- Lifetime = $2,132.40 × 12 months × 18 years
- Lifetime benefit projection = $460,598
Read together: this worker's full retirement age benefit is $2,132.40 per month, adding up to a projected $460,598 over an 18-year retirement. Every figure above was produced by the calculator's engine with inputs birthYear = 1964, currentEarnings = $80,000, yearsWorked = 35, claimAge = 67, lifeExpectancy = 85 (re-verified September 25, 2026).
How Claim Age Changes the Benefit
The single biggest lever you control is the age you claim. The table below holds the earner fixed (eligible 2026, $80,000, 35 years, so PIA = $2,132.40) and varies only the claim age. Every row was computed by the engine.
| Claim Age | Adjustment Factor | Monthly Benefit | Lifetime (to age 85) |
|---|---|---|---|
| 62 (earliest) | 70.00% | $1,492.68 | $411,980 |
| 65 | 86.67% | $1,848.08 | $443,539 |
| 67 (full retirement age) | 100.00% | $2,132.40 | $460,598 |
| 70 (maximum delay) | 124.00% | $2,644.18 | $475,952 |
Claiming at 62 locks in a permanent 30% cut, while waiting until 70 adds 24% in delayed retirement credits -- a swing of more than $1,150 a month for the same worker. Because the reduction and credit are designed to be roughly actuarially fair, the lifetime totals are closer than the monthly amounts suggest: the higher monthly benefit from waiting takes years of collection to overtake the head start of claiming early. That crossover point is your break-even age.
The 62-to-70 Rule of Thumb
For a worker with an FRA of 67, each year you wait past 62 adds roughly 7% to 8% to your monthly benefit, and the total range runs from 70% of PIA at 62 to 124% at 70. The delayed credit stops accruing at age 70, so there is no benefit to claiming later than that.
How Earnings, Bend Points, and COLA Shape PIA
Two forces sit behind the worked example: where your AIME lands across the bend points, which determines how progressive your benefit is, and the cost-of-living adjustment (COLA), which grows the benefit after you turn 62.
Higher Earnings, Diminishing Returns
The table holds everything fixed except earnings (eligible 2026, 35 years, claim at 67) and shows how the 90% / 32% / 15% tiers flatten the benefit as income rises. Every row is engine-computed.
| Annual Earnings | AIME | PIA (monthly at FRA) |
|---|---|---|
| $40,000 | $2,166 | $1,439.00 |
| $60,000 | $3,250 | $1,785.80 |
| $80,000 (worked example) | $4,333 | $2,132.40 |
| $120,000 | $6,500 | $2,825.80 |
| $184,500 (wage base) | $9,993 | $3,562.10 |
Doubling earnings from $40,000 to $80,000 lifts the PIA by about 48% ($1,439.00 to $2,132.40), not 100%. At $184,500 the AIME finally crosses the second bend point ($7,749), so every additional dollar of AIME above it is credited at just 15%. This is exactly how Social Security is designed to replace more income for lower earners.
How the Calculator Handles COLA
The bend points the engine uses are re-indexed each year by SSA using the national Average Wage Index, and they are locked the year you turn 62. That handles wage growth up to eligibility. From the December of that year, SSA applies an annual cost-of-living adjustment (COLA) tied to inflation, whether or not you have claimed. The calculator applies every COLA SSA has already announced. For someone who turned 62 in 2021, that is 5.9%, 8.7%, 3.2%, 2.5% and 2.8% (Decembers 2021 through 2025), which together raise the PIA by about 25%. It does not project future COLAs, so every figure is in 2026 dollars. That keeps the estimate comparable across claim ages, but your actual nominal check will keep growing with each future COLA. The table above is unaffected, because a worker who turns 62 in 2026 has no announced COLA yet. See the SSA COLA page(opens in new tab) for the current adjustment.
A check against SSA’s own number. SSA publishes the maximum benefit for a worker retiring at full retirement age in 2026: $4,152 a month, for someone born in 1959 who earned the taxable maximum every year. The calculator gives that worker about $4,234, roughly 2% high. The whole gap comes from the simplified AIME: it treats the wage base for the year you turned 62 as your career average, where SSA indexes each year’s capped earnings to national wage growth. (Updated September 25, 2026. Before then the calculator left out COLAs and applied the 65% factor after the cap, which put this worker at $2,758.)
Data Sources and Methodology Notes
Calculation Engine and API Access
The same estimate logic runs in the browser and in our public calculator API / MCP server (tool: social_security_estimated_benefit — full input/output schema in the API reference), so a result is identical wherever you access it. The engine returns the monthly benefit at FRA (the PIA after announced COLAs), the PIA before COLAs, the COLAs it applied with a plain-language note, the claim-age-adjusted monthly benefit, the lifetime projection, your FRA, your eligibility year, and a flag for whether the bend points were estimated. As a reproducibility check, the worked example and every table figure on this page were generated by that engine (re-verified September 25, 2026).
Reference Data
- The PIA bend-point formula (90% / 32% / 15%) and the annual bend-point dollar amounts come from the SSA Primary Insurance Amount page(opens in new tab) and the SSA bend-points history(opens in new tab). For 2026 eligibility the bend points are $1,286 and $7,749.
- The 2026 Social Security wage base of $184,500 comes from the SSA contribution and benefit base table(opens in new tab).
- Full retirement age by birth year and the early-reduction / delayed-credit factors follow SSA retirement-age guidance(opens in new tab) (Publication 05-10035).
Assumptions and Scope Limits
- Simplified AIME. The engine approximates AIME from current earnings and years worked, not from your exact 35-year wage-indexed earnings history. Treat the output as a ballpark, not your official benefit.
- 2026 dollars. COLAs SSA has already announced are applied from the year you turn 62. Future COLAs are not projected.
- COLA data source. The COLA history comes from SSA’s cost-of-living adjustment table(opens in new tab); the 2.8% COLA for 2026 is from SSA’s 2026 Social Security Changes fact sheet.
- Retirement benefits only. Spousal, survivor, and disability benefits and taxation of benefits are out of scope.
- No WEP or GPO reduction. The Social Security Fairness Act (Public Law 118-273, signed January 5, 2025)(opens in new tab) repealed the Windfall Elimination Provision and the Government Pension Offset for benefits payable for months after December 2023, so no reduction for a pension from non-covered work applies (see the calculator’s FAQ on the Fairness Act).
- Bend points can be estimated. For an eligibility year beyond the published table, the engine reuses the latest known bend points and flags the result as estimated.
- Figures are 2026 values. Bend points and the wage base are re-indexed annually, so verify the current year before relying on any number.
Check It Yourself
The question. Which bend points does the Social Security benefit formula use for someone who turns 62 in 2026, and what monthly benefit do they give at full retirement age?
Our answer. In the Social Security Calculator, enter birth year 1964, a current salary of $80,000, 35 years worked and a retirement age of 67. The results show eligibility year 2026, bend points of $1,286 / $7,749, and an estimated monthly benefit of $2,132 at 67, which is $2,132.40 rounded to the dollar.
The source. The Social Security Administration's notice Cost-of-Living Increase and Other Determinations for 2026(opens in new tab), published in the Federal Register on November 3, 2025, gives the formula for anyone who first becomes eligible in 2026. Their primary insurance amount (PIA) is 90% of the first $1,286 of average indexed monthly earnings (AIME), plus 32% of AIME between $1,286 and $7,749, plus 15% of AIME above $7,749. SSA then rounds the result down to the next lower multiple of $0.10. AIME itself is rounded down to whole dollars under 20 CFR 404.211(opens in new tab), and under section 216(l) of the Social Security Act(opens in new tab) full retirement age is 67 for anyone who reaches 62 after 2021.
Reproduce it. The worked example above goes through every step: an estimated AIME of $4,333, then 90% × $1,286 = $1,157.40 plus 32% × ($4,333 − $1,286) = $975.04, for $2,132.44, rounded down to $2,132.40. In a spreadsheet, =ROUNDDOWN(0.9*1286 + 0.32*(4333-1286), 1) returns 2,132.40. The bend points and the formula are SSA's; the $4,333 AIME is our calculator's estimate from your current salary, not an SSA figure. For an official estimate based on your actual earnings record, use your my Social Security account at ssa.gov(opens in new tab). If your figure differs from ours, email admin@markcolabs.com with the inputs you used and the figure you got, and we'll compare it against the source.
Frequently Asked Questions
The calculator runs three steps. First it estimates your Average Indexed Monthly Earnings (AIME) from your earnings and years worked. Then it applies the progressive PIA bend-point formula -- 90% of the first tier, 32% of the middle tier, 15% of the top tier -- to turn AIME into your Primary Insurance Amount (PIA), the benefit at full retirement age. Finally it adjusts the PIA up or down for the age you claim. For a worker eligible in 2026 earning $80,000 over 35 years, the engine returns an AIME of $4,333 and a PIA of $2,132.40 per month.
For anyone who turns 62 (becomes eligible) in 2026, the PIA bend points are $1,286 and $7,749. The formula pays 90% of the first $1,286 of AIME, 32% of AIME between $1,286 and $7,749, and 15% of AIME above $7,749. These bend points are locked in the year you turn 62 and do not change afterward, even if you claim later. SSA re-indexes the bend points each year using the national Average Wage Index.
For someone with a full retirement age (FRA) of 67, claiming at 62 permanently reduces the benefit by 30% (to 70% of PIA), and waiting until 70 raises it by 24% (to 124% of PIA) through delayed retirement credits. In the worked example, a $2,132.40 PIA becomes $1,492.68 per month at age 62 and $2,644.18 per month at age 70. The engine applies 5/9 of 1% per month for the first 36 months early, 5/12 of 1% per month beyond that, and 2/3 of 1% per month for each month of delay up to age 70.
It includes the COLAs SSA has already announced, and none beyond them. Your benefit base receives every COLA from the December of the year you turn 62, so someone who turned 62 in 2021 gets the 5.9%, 8.7%, 3.2%, 2.5% and 2.8% COLAs for December 2021 through December 2025. If you turn 62 in 2026 or later, no COLA has been announced for you yet. Either way, figures are in 2026 dollars, and future COLAs are not projected.
The engine uses a simplified single-salary approximation of AIME rather than your full 35-year indexed earnings history, which only SSA holds. It also does not model spousal or survivor benefits, taxation of benefits, or future COLA. For your official figures, create an account and view your Social Security Statement at ssa.gov/myaccount(opens in new tab).
Sources
- Social Security Administration -- Primary Insurance Amount (the 90/32/15 bend-point formula)(opens in new tab)
- SSA -- Benefit Formula Bend Points (2026: $1,286 and $7,749)(opens in new tab)
- SSA -- Contribution and Benefit Base (2026 wage base $184,500)(opens in new tab)
- SSA -- Benefit Reduction for Early Retirement and Delayed Retirement Credits (Publication 05-10035)(opens in new tab)
Important Disclaimer
Disclaimer: This content is for educational and informational purposes only and does not constitute financial, tax, or legal advice. Individual circumstances vary, and you should consult with a qualified financial professional or the Social Security Administration before making claiming decisions. This tool produces a simplified estimate; your official benefit depends on your full earnings record, filing status, and factors such as spousal, survivor, and taxation rules that this calculator does not model. Bend points, the wage base, and cost-of-living adjustments are set by SSA and change from year to year; the figures here are 2026 values. While we strive for accuracy, laws and regulations change over time. Data current as of July 2026.
Content reviewed by Mark at Markco Labs. Learn more about our accuracy standards.