Age calculator
Enter a date of birth to see the exact age, how many days that is, and how long until the next birthday.
Runs in your browser. What you type is not sent to a server.
- Next birthday
- Born on a
- Total months
- Total weeks
- Total days
- Total hours
Your recent calculations
Saved only in this browser, so you can come back to them. Nothing is sent to a server.
How age is counted
Age goes up by one on each birthday. The months and days are counted from the most recent birthday, the same way as the days between dates calculator: born on January 31, you are one month older on February 28 or 29 only once the month has fully passed, so March 1 shows 1 month and 1 day.
If you were born on February 29, this calculator treats March 1 as your birthday in years without a February 29. That is the rule used in the UK and Hong Kong for legal age; some places use February 28 instead.
Total days counts calendar days from the date of birth up to the "age on" date, not including the day of birth. Hours are days times 24, so daylight saving changes are ignored.
Worked examples
Ages below are worked out on November 4, 2026, the same way the calculator does it.
| Date of birth | Age | Days lived | Next birthday |
|---|---|---|---|
| January 1, 2000 | 26 years, 10 months, 3 days | 9,804 | Jan 1, 2027 (in 58 days) |
| June 15, 1990 | 36 years, 4 months, 20 days | 13,291 | Jun 15, 2027 (in 223 days) |
| November 4, 1985 | 41 years exactly | 14,975 | Nov 4, 2027 (in 365 days) |
| February 29, 2008 | 18 years, 8 months, 3 days | 6,823 | Mar 1, 2027 (in 117 days) |
| December 31, 1970 | 55 years, 10 months, 4 days | 20,397 | Dec 31, 2026 (in 57 days) |
The February 29 row shows the leap-day rule: in 2026 the birthday was taken as March 1, so on November 4 the months and days count from March 1.
How old am I if I was born in…
If you only know the year, subtract it from the current year. That gives the age you reach on your birthday this year; before the birthday you are one year younger.
- Born in 1950: turns 76 in 2026
- Born in 1960: turns 66 in 2026
- Born in 1970: turns 56 in 2026
- Born in 1980: turns 46 in 2026
- Born in 1990: turns 36 in 2026
- Born in 2000: turns 26 in 2026
- Born in 2010: turns 16 in 2026
Age in months, weeks, days and hours
Total months are the whole months completed since the date of birth, counted the same way as the years, months and days line above. Total weeks are the days lived divided by seven, with the leftover days shown separately. Hours are days times 24; the calculator works with calendar dates, so daylight saving changes and the time of birth are not counted.
Day-count milestones
Some people celebrate turning 10,000 days old, which happens a little after the 27th birthday. To find the date, set "Age on" forward until days lived reaches the number. For the same birth dates as above:
| Date of birth | 10,000 days old | 15,000 days old | 20,000 days old |
|---|---|---|---|
| January 1, 2000 | Wed, May 19, 2027 | Fri, Jan 25, 2041 | Sun, Oct 4, 2054 |
| June 15, 1990 | Tue, Oct 31, 2017 | Thu, Jul 10, 2031 | Sat, Mar 18, 2045 |
| November 4, 1985 | Fri, Mar 22, 2013 | Sun, Nov 29, 2026 | Tue, Aug 7, 2040 |
| December 31, 1970 | Mon, May 18, 1998 | Wed, Jan 25, 2012 | Fri, Oct 3, 2025 |
10,000 days is 27 years, 4 months and a couple of weeks, depending on how many leap days fall in between: for someone born on January 1, 2000 it lands on May 19, 2027, at 27 years, 4 months and 18 days. Someone born on November 4, 1985 reaches 15,000 days on November 29, 2026, 25 days after their 41st birthday. The add days to a date calculator gets you there in one step: start from the birth date and add 10,000 days.
Leap-day birthdays
For someone born on February 29, the next-birthday line gives both common choices and the next real leap day, for example "Mar 1, 2027 · or Feb 28 if you celebrate it then · next Feb 29: 2028". The age itself follows the March 1 rule described above, so in years without a 29th the age goes up on March 1.
Different ways of counting age
This calculator uses the international system: you are 0 at birth and gain a year on each birthday. Some East Asian traditions counted differently, starting at 1 at birth and adding a year every New Year. South Korea moved official documents to the international system in June 2023, so the age here matches Korean legal age. When a form asks for "age", it almost always means this international age.
Questions
Can I work out an age on a past or future date?
Yes. Change "Age on" to any date after the date of birth, for example to check someone's age on the day a school year starts.
Does it handle leap years?
Yes. Days lived are counted on the real calendar, so every February 29 in between is included, and leap-day birthdays follow the March 1 rule described above.
Why is my age in days different on another site?
Some sites count the day of birth itself, which adds one day. Here the count starts the day after you were born, the same way "days between dates" works.
Is my date of birth sent anywhere?
No. The calculation runs in your browser. A copied link holds only the two dates. Your last few results are listed under the calculator on this device only, and the Clear button next to the list removes them.