Age Calculator
Calculate your exact age in years, months, and days — plus total days lived and your next birthday countdown.
How to use the Age Calculator
- Enter your date of birth.
- The "Calculate Age On" field defaults to today — change it to find your age on any past or future date.
- Click Calculate Age to see your exact age in years, months, and days.
How exact age is calculated
The result counts complete calendar years, then complete calendar months within the remaining partial year, then the remaining days. This matches how age is conventionally expressed and how most countries define legal age milestones.
Privacy — runs in your browser
Your birth date is never sent to a server. All calculations run locally in your browser using the JavaScript Date API. No account or signup is required.
Frequently Asked Questions
Can I calculate age on a future date?
Yes — change the "Calculate Age On" date to any future date. This is useful for checking age eligibility at a future event or deadline.
How is the next birthday calculated?
The tool finds the next occurrence of your birth month and day on or after the "Calculate Age On" date. If that date is your birthday itself, it shows "Today!".
What about leap-year birthdays (Feb 29)?
For people born on February 29, the next birthday in a non-leap year is treated as March 1 by most conventions. This tool places it on Feb 28 in non-leap years to stay on the earlier side.