Age calculator

How to use it

Calculate full age from a date of birth and a reference date. Change the reference date to answer “how old on that date?” instead of only calculating today’s age.

1. Enter the date of birth.
2. Choose the reference date; it initially uses today in the browser.
3. Select Calculate and review the full age in years.

Calculation

reference year − birth year, minus 1 if the birthday has not occurred yet

Reference date

Must not be before birth date

Time of day

Not used

Output

Age in full years

Age changes on the birthday

This is ordinary full-age calculation, not a jurisdiction-specific legal-age rule. If a regulation defines age on a special basis, check that rule separately.