How Social Security Calculates Your Monthly Benefit

Full analysis

Roger Whitney, a retirement planner, walks through the mechanics behind the Social Security retirement benefit calculation. You qualify by earning 40 work credits — roughly 10 years of work, not necessarily consecutive — and credits are based on earnings subject to Social Security tax (in 2026, each credit requires $1,890 in eligible earnings, up to four credits per year). Your benefit is then calculated from your Average Indexed Monthly Earnings (AIME) — the Social Security Administration takes your highest 35 years of earnings, adjusts them for wage growth over time, averages them, and converts the result to a monthly figure. If you worked fewer than 35 years, zeros are inserted for the missing years, which pulls your average — and your eventual benefit — down. That Primary Insurance Amount (PIA) — the benefit you'd receive at full retirement age (currently 67 for most workers not yet claiming) — is the anchor for everything else.