Age calculator
Calculate your exact age in years, months, and days. Find total days lived, hours, weeks, and days until your next birthday — all in your browser.
About the age calculator
The age calculator tells you exactly how old you are, down to the day. Enter your date of birth and it shows your age in years, months, and days — plus the total number of days you've been alive, the day of the week you were born, and how long until your next birthday.
How age is calculated
The calculation subtracts your birth date from the reference date, accounting for varying month lengths and leap years. You're 29 years and 11 months old until the exact day of your 30th birthday, at which point you become 30. This matches how most countries, schools, and government forms define age for official purposes.
Common uses
Age calculators come up in school admissions (where "age as of a specific date" is the official metric), immigration and visa forms, sports eligibility rules, retirement planning, and the occasional curiosity about how many days you've been alive. If you're filling out a form, expand the "calculate as of a different date" option and set it to the application's cutoff date.