How the benefit formula works
Social Security uses a progressive formula designed to replace a larger share of income for lower earners. It starts from your Average Indexed Monthly Earnings (AIME), a monthly figure derived from your 35 highest-earning years adjusted for wage growth.
That AIME is then sliced at two "bend points." The first slice is replaced at 90%, the next slice at 32%, and anything above the second bend point at just 15%. Adding those three pieces together gives your Primary Insurance Amount (PIA) — the monthly benefit you would receive at full retirement age.
Why the replacement rate falls as you earn more
Because each higher slice of earnings is credited at a lower rate, the benefit grows more slowly than income does. A worker with modest AIME may see most of their earnings replaced, while a high earner has a large share of AIME credited at only 15%. The pie chart breaks your PIA into how much each band contributes, making that tilt toward lower earners visible.
Claiming age changes the actual check
The PIA shown here is the benefit at full retirement age. When you actually claim makes a big difference:
- Claiming as early as 62 permanently reduces the monthly amount, by roughly 25–30%.
- Waiting past full retirement age earns delayed retirement credits up to age 70, increasing the benefit by about 8% per year.
- Annual cost-of-living adjustments raise benefits over time to track inflation.
Treat this as an estimate
This calculator uses 2024 bend points and a simplified formula. Your real benefit depends on your full lifetime earnings record, the exact indexing factors, your claiming age, and possible reductions such as the Windfall Elimination Provision. For an official figure, check your statement at ssa.gov.
Formula
PIA = 90%·min(AIME, 1174) + 32%·(min(AIME, 7078) − 1174 if AIME>1174) + 15%·(AIME − 7078 if AIME>7078)Frequently asked questions
- What is AIME?
- Average Indexed Monthly Earnings is your highest 35 years of earnings, indexed for wage growth, averaged to a monthly figure. The Social Security Administration computes it from your record.