Age Calculator
Find your exact age in years, months, and days — plus total weeks and days lived, and a countdown to your next birthday.
How age is calculated
Your age in years, months, and days is the calendar difference between your birth date and the target date, "borrowing" days and months where needed — the same way you'd work out a duration on paper. The totals (months, weeks, days) count actual elapsed calendar time, so leap days are already included.
Born March 15, 1990, measured on July 22, 2026: that's 36 years, 4 months, 7 days — about 436 months or 13,278 days.
Beyond birthdays
The same date math answers a lot of practical questions: eligibility ages (driving, voting, retirement accounts), how old someone will be at a future event, or a pet's age. Change the "age at" date to any past or future day to see the age on that date. To count the gap between two arbitrary dates rather than an age, use the date calculator; for durations in hours and minutes, the time calculator.
Frequently asked questions
How do I calculate my exact age?
Calendar difference between birth date and today, in years, months, and days — plus totals in weeks and days.
How is age calculated across leap years?
Actual calendar days are counted, so leap days are included automatically.
Can I calculate age at a past or future date?
Yes — set the "age at" date to any day.
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Last reviewed: July 2026.