Whether you need your exact age for a form, want to know how many days are left until your next birthday, or need to calculate how old someone was on a specific date, this calculator handles it instantly — accounting correctly for different month lengths and leap years.
How to use the age calculator tool
- 1
Enter your date of birth
Pick the birth date you want to calculate from.
- 2
Choose the "as of" date
Defaults to today, but you can pick any date — useful for calculating age at a past or future event.
- 3
Read the result
See the exact age in years, months, and days, plus total days and weeks lived.
Common use cases
Check eligibility by age
Calculate exact age as of a specific cutoff date for an application or eligibility requirement.
Plan around a birthday
See exactly how many days are left until the next birthday.
Calculate age at a past event
Find out how old someone was on a specific historical date.
Frequently asked questions
It counts full calendar years, then full months within the remaining period, then remaining days — the same way you'd count age by hand, accounting for different month lengths and leap years.