How old am I, exactly?
Your age in years is the number of birthdays you have had. That is the big number at the top. Below it, the calculator goes further: it counts the full years, then the full months since your last birthday, then the days left over. That is how age is counted on forms, insurance quotes and ID checks. Born on March 15, 1990? On November 2, 2026 you are 36 years, 7 months and 18 days old.
Everything is worked out in your browser. Your birth date stays on this device, so the page remembers it next time without sending it anywhere.
How the calculation works
- Full years. Count the birthdays that have already happened. Before this year’s birthday, you are one year younger than “this year minus birth year”.
- Full months. From your last birthday, count the months until the same day number. Born on the 15th, a month passes on each 15th.
- Days left. Count the days from that last monthly date to today.
Months do not all have the same length, so one rule matters: when the same day number does not exist in a month, the month ends on its last day. Someone born on January 31 is one month old on February 28 (or 29 in a leap year), not on March 3.
| Born | Age | On |
|---|---|---|
| March 15, 1990 | 36 years, 7 months, 18 days | November 2, 2026 |
| July 1, 1960 | 65 years, 11 months, 29 days | June 30, 2026 |
| January 31, 2026 | 1 month, 1 day | March 1, 2026 |
| February 29, 2000 | 26 years | February 28, 2026 |
| December 31, 1999 | 1 day | January 1, 2000 |
Days, weeks and hours lived
The second line counts every day since you were born. The day of your birth is day 0, so on your first birthday you are 365 days old, or 366 if a February 29 came in between. Weeks are full weeks. Hours are simply days times 24: the time of birth and clock changes are left out, which is why the page says “about”.
Two milestones people like to celebrate: you turn 10,000 days old at about 27 years and 4.5 months, and one billion seconds at about 31 years and 8 months. Switch the big number to Days to watch the first one coming.
Your next birthday
The last line tells you how many days remain until your next birthday, which age you will turn, and on which day of the week it falls. A birthday moves forward one weekday each year, and two weekdays when a February 29 falls in between. The same line also tells you the day of the week you were born. For any other date, the day of the week calculator does the same, and the countdown can count down to the big day.
Babies, months and weeks
For babies and toddlers, years are too coarse. Doctors and parents count in weeks for the first months, then in months until about age two: an “18-month” checkup, “9 months old”. Tap Months to make the month count the big number, or Days to see the day count. The line below still gives the years, months and days, so “1 year, 2 months and 5 days” and “14 months” describe the same child.
The age gap between two people
To find the age difference between two people, put both birth dates in the date calculator: the line under the result gives the gap in years, months and days. The gap never changes, but it feels smaller every year: 10 years between ages 5 and 15 is a lot, between 40 and 50 it is nothing.
Born on February 29
About one person in 1,461 is born on a leap day. In common years, this calculator treats February 28 as the anniversary: you turn a year older at the end of February, never in March. Laws do not all agree, and some count March 1 instead, so check the local rule when an exact legal age matters. Note that 2100 will not be a leap year: years ending in 00 are leap years only when they can be divided by 400.
Age on another date
Tap “today” in the sentence and pick any date to see how old you were or will be that day. Useful cases:
- Forms and deadlines: some rules use your age on a set day, such as December 31 for youth sports categories or the first day of school.
- Legal ages in the US: 18 to vote, 21 to buy alcohol, 65 for Medicare.
- Retirement: full retirement age for Social Security is 66 to 67 depending on your birth year. Each birth year page gives the exact figure.
- Family dates: how old you were at a wedding, or how old a parent will be at a graduation.
Other ways of counting age
Not every culture counted the same way. In the traditional Korean system, a baby was one year old at birth and everyone gained a year on January 1. South Korea switched its official documents to the international count on June 28, 2023, making many people a year or two younger overnight. Some life insurers also price policies on your age at your nearest birthday rather than your last one. This calculator always gives the international count: full years since birth.
Look up a birth year
Each birth year has its own page, with the age reached every year, the generation, the Chinese zodiac sign and key dates: born in 1960, 1970, 1980, 1990, 2000 and 2010. To count the days between any two dates, use the date calculator.