Age Calculator

Milestones that depend on your exact age

Many US rules switch on at a specific birthday, so knowing the exact date helps with planning:

• 26: under the Affordable Care Act, you can generally stay on a parent’s health plan until you turn 26. Coverage often ends at the end of that month, so plan for new insurance before then.
• 59½: withdrawals from 401(k) plans and IRAs before this age usually carry a 10% extra tax, with some exceptions. The calculator shows the exact date you reach 59½.
• 62, full retirement age and 70: Social Security retirement benefits can start at 62 but are reduced. They reach 100% at your full retirement age and keep growing until 70.
• 65: Medicare eligibility. Your initial enrollment period starts three months before the month you turn 65.

How the calculation works

Age is counted in whole calendar years first, then whole months, then leftover days. For example, someone born on January 31 is one month older on the last day of February, because February has no 31st. Totals in days and weeks count every calendar day, including leap days.

These milestones are general US rules. Your plan, state or situation may differ, so confirm important dates with the relevant agency or provider.