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Age calculator
This age calculator works out exact age from a date of birth. You get years, months and days, plus total months, weeks, days and hours, the weekday of birth and the days until the next birthday.
Loading the age calculator.
How to use the age calculator
- Date of birth. Pick the birth date from the calendar or type it in.
- Age on. Leave this on today to answer “how old am I right now”. Change it to any other day to get the age on a date in the past or the future.
The result updates as soon as both dates are filled in. The large figure is the age in years, months and days. Below it you see the same age as total months, weeks, days and hours, the day of the week the person was born, and how many days are left until the next birthday.
How age is calculated by date of birth
The calculator counts on the real calendar. It does not assume every month has 30 days or every year has 365.
Age = full years since birth + full months since the last birthday + days since the last monthly anniversary
Worked example
Someone was born on 15 June 1995. How old are they on 1 March 2026?
- Last birthday: 15 June 2025. That is 2025 − 1995 = 30 full years.
- Full months since then: 15 June 2025 to 15 February 2026 is 8 months.
- Days left over: 15 February to 1 March 2026 is 14 days, because February 2026 has 28 days.
- Age: 30 years, 8 months, 14 days.
In other units that is 368 months, 1,602 full weeks or 11,217 days. The birth date was a Thursday, and the next birthday is 106 days away.
How tricky dates are counted
Month ends and leap days are where age sums usually go wrong. This is what the calculator returns.
| Date of birth | Age on | Result |
|---|---|---|
| 31 December 1999 | 1 January 2000 | 1 day |
| 31 January 2026 | 1 March 2026 | 1 month, 1 day |
| 31 August 2025 | 30 September 2025 | 1 month, 0 days |
| 29 February 2000 | 29 February 2024 | 24 years, 0 days |
| 29 February 2000 | 28 February 2026 | 26 years, 0 days |
If the birth day does not exist in a month, the last day of that month counts as the anniversary.
Which age calculator do I need?
- A person of any age. Use this page. It also works as a chronological age calculator for test scoring and school forms.
- A baby under two. The baby age calculator gives age in weeks and days, and adjusted age for babies born early.
- A dog. The dog age calculator turns dog years into human years by breed size.
- Two dates that are not a birthday. Use days between dates to count the gap.
Good to know
- Chronological age. This is the time since birth in years, months and days. Some test manuals count every month as 30 days. This calculator uses real month lengths, so follow the manual if the two differ by a day.
- Leap day birthdays. In a year without 29 February, the calculator counts the birthday on 28 February. Some countries treat 1 March as the legal birthday, so check local rules for official deadlines.
- Hours. Hours are counted as whole days times 24. The calculator does not ask for a time of birth.
- Other age systems. The result is international age, which starts at zero on the day of birth.
How this calculator was checked
Built by Rasel Hakkani, WordPress developer at Swift Web Dev. The results were checked against hand-counted dates, including 29 February birthdays, months of different lengths and dates of birth in the future.
Last checked: October 2026. Found a wrong answer? Tell us and we will fix it.
Age calculator questions
How do I calculate my age from my date of birth?
Subtract your birth year from the current year. Take one off if your birthday has not happened yet this year. Then count the full months since your last birthday and the days left over. The calculator does all three steps for you.
What is chronological age?
Chronological age is the exact time since birth, written as years, months and days. Teachers, speech therapists and psychologists use it to score age-based tests. Enter the date of birth and the test date in the Age on field to get it.
How is age counted for a 29 February birthday?
In a leap year the birthday is 29 February. In other years this calculator counts it on 28 February, the last day of the month. Someone born on 29 February 2000 is 26 on 28 February 2026.
Can I find my age on a specific date?
Yes. Change the Age on field to any date after the date of birth. Use a past date to see how old someone was at an event, or a future date to see how old they will be.
How many days old am I?
Enter your date of birth and read the Total days figure. It counts every calendar day from your birth date to the Age on date, leap days included. Someone born on 15 June 1995 is 11,217 days old on 1 March 2026.
Is the age calculator free?
Yes. It runs in your browser, needs no account and does not save or send the dates you enter.
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