Age Calculator
This age calculator tells you exactly how old you are in years, months, and days from your date of birth. Pick your birthday and you'll get the full breakdown, your age in total months, weeks, days, and hours, and a countdown to your next birthday. Want your age on a past or future date? Just change the second box. It's free, private, and leap-year aware.
- Years, months & days
- Age at any date
- Total weeks & days
- Next birthday
- Leap-year aware
Last updated June 17, 2026 Counts completed years Reviewed by the Calcowa team
The birth date has to be on or before the age-at date.
Pick any two dates. Leave the second on today to see your age right now.
How old am I, exactly?
Your exact age is the time you've completed since birth, written as full years, then the months past your last birthday, then the days past that. The trick is the borrowing: when today's day sits earlier in the month than your birth day, you drop a month and add that month's length in days. A person born on January 1, 2000 is 26 years, 5 months, and 16 days old on June 17, 2026. This age calculator runs the borrowing and the leap years for you, so you don't second-guess the count.
How the age is worked out
Here's the path for a birth date of January 1, 2000 measured on June 17, 2026. It's the same method you'd use by hand:
- 1
Subtract the years2026 minus 2000 is 26 full years, before checking the month and day.
- 2
Subtract the monthsJune is month 6, January is month 1, so 5 months sit past the last birthday.
- 3
Subtract the daysThe 17th minus the 1st is 16 days, with no borrowing needed here.
- 4
Borrow when neededIf the day went negative, you'd drop a month and add that month's days, then settle up.
One year in other units
Here's how a single year breaks down, which is why the total-days and total-hours figures climb so fast. The averages use 365.25 days a year to fold in leap years, so they're a touch above a flat 365. If you're curious why the hours look huge, it's just days times 24.
| Span | Months | Weeks | Days |
|---|---|---|---|
| 1 year | 12 | 52.18 | 365.25 |
| 5 years | 60 | 260.9 | 1,826 |
| 10 years | 120 | 521.8 | 3,653 |
| 25 years | 300 | 1,304 | 9,131 |
Frequently asked questions
Count the full years from your birth date to today, then the leftover months, then the leftover days. If today's day is earlier in the month than your birthday, you borrow a month and add its days, the same way you borrow when subtracting. This age calculator does that for you the moment you pick a date, so you don't have to track leap years or month lengths by hand.
Your exact age is the completed years, months, and days since you were born, not a rounded number. Someone born on January 1, 2000 is 26 years, 5 months, and 16 days old on June 17, 2026. The tool above shows that full breakdown, plus your age in total months, weeks, days, and hours, so you'll see it whichever way you need it.
Completed age is the years you've actually finished living, which is the everyday meaning and what this tool shows. Running age, used in some countries and forms, counts the year you're currently in, so a person of completed age 25 is in their 26th running year. If a form asks for running age, add one to the completed years here.
Yes. February 29 birthdays and leap years are built into the math, so the day and month counts stay correct across them. For the total-days figure, each leap year adds its extra day automatically. If you were born on a leap day, the tool counts your birthday on February 29 in leap years and rolls it to March 1 in common years for the countdown.
The tool finds your birth month and day in the current year, and if that date has passed it looks at next year, then counts the days from today. So if your birthday is in three weeks, you'll see 21 days. It's a quick way to plan a party or just see how close the date is, and it updates the instant you change the birth date.
Yes on both. There's no sign-up, no limit, and nothing to install, since it runs right in your browser. The dates you enter never leave your device, so nothing gets sent to a server. Bookmark the page and you'll have a quick, private way to check anyone's exact age whenever you need it.
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