How Old Am I? Exact age calculator
Adds hours and minutes to your age.
Age on a different date?
Leave blank to use today, or set a past or future date to find your age then.
Enter your date of birth and press Calculate to see your exact age, the totals, your birthday facts, and a countdown to your next birthday.
Enter your date of birth (and your birth time, if you know it) to find your exact age in years, months, and days, plus running totals in weeks, hours, minutes, and seconds. You will also see the day of the week you were born, your zodiac sign, and a live countdown to your next birthday. Need the gap between two arbitrary dates instead? Try the time duration calculator .
How Your Exact Age Is Calculated
Your age can be expressed two ways, and this calculator shows both. The calendar form (years, months, days) counts whole birthdays first, then whole months since your last birthday, then the leftover days. The totals form simply measures the elapsed time and converts it: total days, hours, minutes, seconds. The two always agree, but they answer slightly different questions.
The "months" part is the slippery one. Months range from 28 to 31 days, so "3 months" is not a fixed amount of time, it depends on which months you crossed. The calculator handles this with a borrowing method: when the day-of-month math goes negative, it borrows the real length of the previous month, just as you would borrow in long subtraction.
Leap years matter too. A February 29 every four years (skipping most century years) keeps the calendar aligned with the Earth's orbit, and it is why your age in total days is not simply years times 365. Born on February 29? See the FAQ below for how your birthday is handled.
Fun Ways to Measure Your Age
Birthdays come once a year, but other milestones are hiding in the totals. Your 10,000th day arrives a few months after your 27th birthday, and day 20,000 lands in your mid-50s, both make great excuses for a party nobody else thought to throw. Week counters work the same way: your 2,000th week falls just past age 38.
The bigger units get dizzying fast. By age 30 you have lived roughly 263,000 hours, nearly 16 million minutes, and close to a billion seconds, with the billionth second itself ticking over at about 31.7 years old. And since a resting heart beats around 100,000 times a day, a 40-year-old's heart has already managed well over a billion beats.
Run your own numbers in the calculator above, then watch the seconds counter climb every time you press Calculate. For more date and time tools, browse our free calculators .
Your Birthday Facts
The calculator also tells you which day of the week you arrived on. The weekday of your birthday drifts forward one day each year, two when a leap day intervenes, which is why the full pattern only repeats every 28 years on the Gregorian calendar.
Your western zodiac sign comes straight from your birth month and day. The twelve signs divide the year roughly along these lines: Aries (Mar 21–Apr 19), Taurus (Apr 20–May 20), Gemini (May 21–Jun 20), Cancer (Jun 21–Jul 22), Leo (Jul 23–Aug 22), Virgo (Aug 23–Sep 22), Libra (Sep 23–Oct 22), Scorpio (Oct 23–Nov 21), Sagittarius (Nov 22–Dec 21), Capricorn (Dec 22–Jan 19), Aquarius (Jan 20–Feb 18), and Pisces (Feb 19–Mar 20).
Finally, the next-birthday countdown shows the exact date and weekday of your upcoming birthday and how many days remain, handy for planning, and a guaranteed mood boost when the number hits zero.
Frequently Asked Questions
Multiply your full years by 365, add one day for each leap year you have lived through, then add the days since your last birthday. The calculator above does this exactly: enter your date of birth and it returns your age in total days, plus weeks, hours, minutes, and seconds.
If you were born on February 29, your true calendar birthday only occurs in leap years (about one year in four). In other years, most people and this calculator treat February 28 as the observed birthday, while some jurisdictions use March 1 for legal purposes. Your age in total days is unaffected either way.
Most of the world uses the international system this calculator uses: you are 0 at birth and gain a year on each birthday. Traditional East Asian age reckoning works differently: you are 1 at birth and everyone gains a year at New Year, so your Korean age could be one or two years higher. South Korea officially switched to international age in 2023.
Enter your date of birth in the calculator above and it tells you instantly, Monday through Sunday. The calendar repeats on a complex cycle (your birthday weekday usually advances one day per year and two after a leap day), so the tool computes it directly from the calendar rather than estimating.
The calculator counts the days from today to your next birthday and shows the exact date and weekday it falls on. If today is your birthday, it skips the countdown and wishes you a happy birthday. February 29 birthdays count down to February 28 in non-leap years.