Age Calculator
Calculate exact age in years, months, and days from a date of birth. Nothing you enter leaves your browser.
Frequently asked questions
- How is age calculated exactly?
- The calculator finds the most recent birthday anniversary on or before the date you're comparing against, then counts the years, months, and remaining days from there. This correctly handles edge cases like birthdays on the 31st of a month, and February 29th birthdays in non-leap years.
- What happens with a February 29 birthday in a non-leap year?
- In years without a February 29th, the calculator treats February 28th as the anniversary date for age purposes, which is the common convention — you won't see the age or next-birthday countdown break in non-leap years.
- Can I calculate age as of a specific date, not just today?
- Yes — the second field lets you calculate age as of any date, useful for things like eligibility checks, legal age requirements on a specific date, or figuring out how old someone was during a past event.
- Is my birth date sent anywhere?
- No. All calculation happens in your browser using JavaScript's built-in date handling — nothing is transmitted or stored.