Age calculator

Calculate completed years of age and calendar-year age from a birth date and reference date.

These results use the example values shown above.

Age on the reference date

Age 26 years

Calendar-year age26 years

Reference date2026-10-05

Not a legal, insurance or eligibility determination. For February 29 births, this calculation increases age on March 1 in non-leap years.

How to use Age calculator

Enter the birth date and the date on which to calculate age. Both stay in your browser.

Completed age subtracts one year if the birthday has not yet occurred. Calendar-year age is simply reference year minus birth year.

Example
Someone born October 3, 2000 is 25 on October 2, 2026, and 26 from October 3.

What is calendar-year age?

The difference between the two calendar years, regardless of birthday.

Is the birth date stored?

No. It is only used for the local calculation.

Reviewed: 2026-10-04 · Report an issue