Age Calculator — Years, Months, Days & Live Counter
Free age calculator with calendar-accurate years/months/days, total days lived, live hours/minutes/seconds counter, and a next-birthday countdown.
Notes on the calculation
- Years/months/days uses calendar-aware borrowing (handles 28/29/30/31-day months and leap years).
- Hours/minutes/seconds live-tick once per second when the target is today.
- The next-birthday countdown rolls to the following year if your birthday this year has already passed.
- Time zone is your browser's local zone. Birth and target are interpreted at midnight local time.
About this tool
Age is conceptually simple — the time elapsed between birth and now — but calendar arithmetic makes it messier than you might expect. Months have different lengths, leap years insert an extra day, and time zones can shift the boundary. WRRK's age calculator does the right thing: it computes calendar age the same way governments and legal systems do, with month-by-month borrowing that respects 28/29/30/31-day months and leap years.
On top of that, we show fun extras: total days lived (great for "guess how many days I've been alive"), a live counter that ticks every second while you watch the page, and a next-birthday countdown that rolls automatically to the following year once this year's birthday has passed.
The target date defaults to today but you can change it freely — handy for "how old will I be when I retire?" or "how old was Grandma at my wedding?" The math runs in your browser so nothing is uploaded.
How to calculate age (5 steps)
- Enter date of birth. Use the date picker. Any year supported by the browser (typically 1900 onwards) works.
- Enter the target date. Defaults to today. Change it for a future event, an anniversary, or a historical date.
- Read years/months/days. Right panel shows the precise calendar age, calculated with proper month and leap-year borrowing.
- Watch the live counter. When the target is today, hours/minutes/seconds tick once per second so you can watch yourself age in real time.
- Check next birthday. The bottom of the result panel shows the date of your next birthday and the number of days until it.
Use cases
- Filling out forms that ask for exact age
- Calculating eligibility (driving age, voting age, retirement)
- Anniversaries — exact years, months and days married
- Pet ages — calculate for any species' date of birth
- Genealogy — age of ancestors at historical events
- Project timelines — exact duration between two milestones
- Baby age in months and days for parents
Frequently asked questions
+−How is age calculated?
We compute the calendar difference between birth date and target date. Subtract years; if the target month/day is before the birth month/day, borrow one year and add 12 months. Then for days, if the target day is before the birth day, borrow one month and add the number of days in that previous month. This handles leap years correctly.
+−What time zone does the live counter use?
Your browser's local time zone. Both the birth date and the target date are interpreted at midnight local time, and the live hours/minutes/seconds tick uses your device clock.
+−Why do years and months sometimes look 'off' compared to other calculators?
Some calculators use a simplified 30-day month or 365.25-day year, which gives different results in months and days. We use true calendar arithmetic with month-by-month borrowing — the same method used in legal age calculations and most government systems.
+−Can I calculate age between two past dates (not today)?
Yes. Set the target date to whatever you need — a wedding anniversary, a historical date, the date of a future event. The calculator works for any target date on or after the birth date.
+−How is total days lived computed?
Difference in milliseconds between the two dates, divided by 86,400,000 (ms in a day). When the target is today, we use the live moment so seconds tick. We floor the result so partial days don't count.
+−Is my date of birth stored anywhere?
No. The calculator runs entirely in your browser. Nothing is sent to a server, logged, or stored. Reload the page and the data is gone.
+−Why is my next birthday more than 365 days away?
It can't be — but rounding to whole days plus a leap year can put it at 366. If your birthday this year has passed, the calculator rolls to next year and counts the days from your target date until then.