Age Calculator
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An age calculator computes your exact age in years, months, and days from your birth date to today (or another target date). Useful for official documents, medical records, eligibility verification, and birthday countdowns.
Tip: For official purposes (passport, contracts, benefits), age is measured in completed years — you are 35 until your 36th birthday, not the day you turn 35. Check the specific rule if precision matters.
- 1Subtract birth year from current year for years
- 2Adjust if the birthday hasn't occurred yet this year (subtract 1 year)
- 3Calculate remaining months and days similarly
- 4Leap day birthdays (Feb 29): age counted Feb 28 or March 1 in non-leap years (varies by jurisdiction)
| Age | Milestone |
|---|---|
| 13 | COPPA — children's online privacy law applies |
| 16 | Driving age (most US states) |
| 17 | Can join military with parental consent |
| 18 | Legal adult — vote, sign contracts, military |
| 21 | Alcohol, handgun purchase |
| 25 | Car rental without surcharge; brain fully developed |
| 35 | Minimum age for US President |
| 65 | Medicare eligibility |
| 67 | Full Social Security retirement age (born 1960+) |
Fun Fact
Different cultures define age differently. In South Korea, the traditional system adds 1 year at birth (counting the time in the womb) and adds another year on New Year's Day, not your birthday. South Korea officially switched to the international standard in 2023.
References