Age Calculator
Calculate your exact age in years, months, days, weeks, and total days from your birth date.
How do you calculate exact age in years, months, and days?
Start with birth date and current date. Calculate years (current year - birth year), then months and days. Adjust if birthday hasn't occurred yet this year. Example: Born Jan 15, 1990, today is March 20, 2024 = 34 years, 2 months, 5 days. Total days = 12,483 days = 1,783 weeks. This accounts for leap years automatically. Useful for: Legal age verification, milestone tracking, age requirements.
Why does my age in total months differ from years x 12?
Total months counts every month lived, including partial years. Example: 5 years, 3 months = 63 total months (5x12 + 3). But calendar months vary (28-31 days), so calculations use average month length. Total days is most accurate measure. Age in months useful for: Baby development (0-24 months), pet age, subscription durations, medical records.
When do I turn a specific age?
You turn a new age at 12:00 AM on your birthday, regardless of birth time. Legal age changes at midnight. Example: Born June 15, 2005 at 3:00 PM - you turn 18 at 12:00 AM on June 15, 2023. Some countries count differently: Korea adds 1 year at birth and 1 on New Year's. Western age = Korean age - 1 or 2. Calculator uses standard Western aging.
How accurate is this age calculator?
Highly accurate - accounts for leap years, varying month lengths, and exact days. Uses JavaScript Date functions for precision. Limitations: Dates before 1900 may be less accurate (calendar changes), doesn't account for timezone differences (uses local time), historical calendar reforms (Julian to Gregorian 1582). For modern dates (1900+), accurate to the day.