Age Calculator
Calculate fully elapsed calendar years, months, and days from a birth date to a selected date.
Result
Enter a date of birth and an as-of date.
This is the fully elapsed time between two calendar dates. Legal age rules may vary by country or authority.
How It Is Calculated
The calculator counts fully elapsed years, months, and days from birth to the as-of date.
Check the relevant authority's rules when an official or legal age calculation is required.
Calendar age versus elapsed days
A calendar age counts fully completed years, months, and days between two dates. The total-day value answers a different question: it measures the complete elapsed interval without grouping it into calendar units.
Where the result needs context
Age calculations are useful for records, anniversaries, and eligibility checks, but legal age rules can define the effective date differently. Confirm the rule used by the relevant country or organization before making an official decision.
Frequently Asked Questions
What is the as-of date?
It is the date on which you want to know the age. It defaults to today's date in your browser.
Does it handle February 29 birthdays?
Yes. It calculates calendar elapsed time using leap years and the actual number of days in each month.
Is the result the same in every country?
The elapsed calendar period is calculated consistently, but legal or administrative age rules may vary by country or authority.