Age Calculator
Calculate age from a date of birth and an as-of date.
About this tool
This age calculator determines completed years and additional months between a date of birth and an as-of date. It can be used for general age checks and date planning. It reports years and months rather than a full day-by-day duration.
How to use this calculator
- Choose the date of birth.
- Choose the date on which age should be measured.
- Calculate and review the completed years and additional months. Make sure the as-of date is not earlier than the birth date.
Formula
Worked example
If the birth date is 15 June 1990 and the as-of date is 15 June 2025, the completed age is 35 years.
Frequently asked questions
Can I calculate age on a past or future date?
Yes. Change the “As of” date to the date you want to check. A future date gives a projected age, not the person’s current age.
Does this show exact age in days?
No. This page reports years and additional months. For legal eligibility based on an exact date, check the relevant official requirement.
How are leap-day birthdays handled?
Calendar calculations around 29 February can depend on the convention used. Confirm the applicable rule if the result affects eligibility or a legal deadline.
What if the as-of date is before the date of birth?
That is not a valid age interval. Select an as-of date on or after the birth date.
EzCalcTools provides general calculations for information and planning. Results depend on the values and assumptions entered. For financial, investment, payroll or tax decisions, confirm the applicable product terms and current rules with an authoritative source or qualified professional.