How Exact Age Is Calculated
Calendar age is trickier than it looks: months have 28–31 days and leap years add a day every four years (minus century exceptions). This calculator counts full calendar years first, then full months, then remaining days — the same convention used on official documents — and handles leap years correctly.
Worked Example
Born March 15, 1990, checked on July 11, 2026: exactly 36 years, 3 months, 26 days — 13,267 total days, roughly 1,895 weeks or 318,408 hours. Next birthday: 247 days away.
Fun Age Milestones
- 10,000 days old lands around age 27.4 — a popular "second coming-of-age".
- 1 billion seconds is about 31.7 years.
- 500 months is about 41.7 years.
Leap-Day Birthdays
Born February 29? Common law jurisdictions typically treat March 1 as the legal birthday in non-leap years; this calculator counts your next actual birthday celebration accordingly. Either way, you only get a "real" birthday every four years — enjoy them.