Social Security is the foundation of retirement income for most Americans — yet almost nobody knows exactly how their benefit is calculated. This guide walks through the real 2026 formula the Social Security Administration (SSA) uses, with the official numbers, so you can estimate your own benefit and avoid the costly mistake of claiming at the wrong time.

You can compute your benefit right now with our free Social Security calculator. The steps below show you what it does behind the scenes.

Step 1: Your 35 Highest-Earning Years → AIME

SSA indexes your historical earnings for wage growth, then takes your **35 highest-earning years**, divides by 420 (35 years × 12 months), and arrives at your **Average Indexed Monthly Earnings (AIME)**.

If you have fewer than 35 years of covered earnings, the missing years count as **zero** — which is why working 35 years (or more) materially raises your benefit.

Step 2: AIME → Primary Insurance Amount (PIA)

Your PIA is the monthly benefit at **full retirement age (FRA)**, computed by applying "bend points" to your AIME. For 2026, the bend points are approximately:

  • •**90%** of the first **~$1,195** of AIME (monthly).
  • •**32%** of AIME between **~$1,195 and ~$7,200**.
  • •**15%** of AIME above **~$7,200**.

Example: if your AIME is $5,000, your 2026 PIA ≈ 0.90×$1,195 + 0.32×($5,000 − $1,195) = $1,075.50 + $1,217.60 = **$2,293/month** at full retirement age.

Official rates and bend points are published by the SSA each year — see the Social Security Administration for the precise figures.

Step 3: Full Retirement Age (FRA) by Birth Year

Your PIA is paid in full only if you claim at your FRA. Claim earlier and it is permanently reduced; claim later and you earn delayed-retirement credits up to age 70.

  • •Born 1943–1954: FRA = **66**.
  • •Born 1955–1959: FRA rises gradually to **66 and 10 months**.
  • •Born 1960 or later: FRA = **67**.
  • •Claiming at 62 vs 67 can cut your benefit by up to **30%**; delaying to 70 adds about **8% per year** of credits (24%+ over FRA).

Spousal, Survivor, and Ex-Spouse Benefits

A qualifying spouse can receive up to **50% of the worker's PIA** at the spouse's FRA, even with no earnings record of their own. Survivor benefits can be up to **100% of the deceased worker's benefit**, and an ex-spouse may qualify on a former spouse's record if the marriage lasted 10+ years.

These family benefits make the *claiming-age decision* a household optimization problem, not just an individual one — see our guide on optimizing your Social Security claiming age.

Cost-of-Living Adjustments (COLA)

Benefits are inflation-indexed. The annual COLA is based on the CPI-W. A 3% COLA on a $2,293 PIA adds roughly $69/month the following year — a built-in hedge most private pensions lack.

Is Your Social Security Taxable? (Provisional Income)

Up to **85%** of benefits can be taxable if your "provisional income" (AGI + tax-exempt interest + half of benefits) exceeds $34,000 (single) or $44,000 (married filing jointly). This is a common, expensive surprise in retirement.

Plan for it with our breakdown of Social Security taxation and provisional income.

2026 Action Checklist

  1. Create a my Social Security account and verify your earnings record for errors.
  2. Decide your claiming age using the 62 / FRA / 70 trade-off and your life-expectancy assumptions.
  3. Coordinate spousal/survivor strategies as a couple, not individually.
  4. Model the tax hit from provisional income inside your retirement withdrawal plan.
  5. Run the number in our Social Security calculator before any final decision.