How the chart works
Full retirement age used to be 65 for everyone. A 1983 law raised it in steps: to 66 for people born from 1943 to 1954, then two months at a time for those born from 1955 to 1959, and to 67 for anyone born in 1960 or later. No change since then has moved it again.
Claiming early cuts your check by five-ninths of 1% for each of the first 36 months before full retirement age, and five-twelfths of 1% for each month beyond that. Waiting past full retirement age adds two-thirds of 1% a month, or 8% a year, until 70. That is why the share at 62 shrinks and the share at 70 falls as full retirement age rises.
If you were born on January 1, use the year before. Social Security treats you as reaching each age the day before your birthday.