Claim early at 62 and checks start sooner but shrink to 70% for life. Wait until 70 and they grow to 124%. This finds your break-even ages and the claiming age that pays you the most over a lifetime.
The benefit adjustment. Your FRA benefit is 100%. Claim earlier and it's reduced by 5/9 of 1% per month for the first 36 months early, then 5/12 of 1% for any month beyond that — so at 62 with an FRA of 67 you get 70%. Claim later and you earn delayed retirement credits of 2/3 of 1% per month (8% per year) up to age 70, which caps at 124%. These are the official SSA formulas.
Lifetime total. For each claiming age, the calculator pays that monthly amount from the claim date until your plan-to age, growing every year by the COLA. Summing those payments gives the lifetime total. Claiming later means fewer checks but each is much larger — the chart shows where the bigger checks overtake the head start.
Break-even age is where a later claim's cumulative total catches and passes an earlier one. If you expect to live past the break-even, waiting wins; if not, claiming earlier does.
Present value option. Money has a time value — a dollar at 80 is worth less than a dollar today if you could invest in between. Turning this on discounts every future payment back to today's value at your chosen rate, which pushes the optimal age earlier. With it off, you're comparing raw dollars.
This tool covers a single individual's retirement benefit. It doesn't model spousal or survivor benefits, the earnings test if you keep working before FRA, or taxation of benefits — all of which can shift the answer. Treat it as a strong first cut, not the final word.