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Calculate Your Exact Age
This free age calculator works out exactly how old you are from your date of birth, in years, months, and days, along with the same span as total days, total weeks, and total months. It also works as a date difference calculator: enter any start date and any end date to see the time elapsed between them.
The end date starts on today’s date, so picking a birth date is enough to answer “how old am I?” Change the end date to find someone’s age on a past date or how old they will be on a future one. If you only need a plain day count, or want to add or subtract days or count business days, the days calculator is built for that.
How to Use the Age Calculator
- 1
Enter the date of birth
Pick a birth date, or any start date you want to measure from, in the first date field.
- 2
Set the end date
The "To Date" field starts on today’s date. Leave it to get your current age, or change it to any past or future date.
- 3
Read the exact age
The result appears instantly as years, months, and days, for example 36y 4m 15d.
- 4
Check the totals
Below the main result, read the same span as total days, total weeks, whole years, and total months.
Everything is calculated in your browser as you pick the dates. Your date of birth is not uploaded or stored, and no account is needed.
How Age Is Calculated
Age is counted the way people count birthdays, not by dividing a day count by 365. The calculator first finds how many whole years fit between the two dates, then how many whole months fit after that, and finally counts the days left over. Taking a birth date of May 15, 1990 and an end date of September 30, 2026:
- Years: May 15, 1990 to May 15, 2026 is 36 whole years.
- Months: May 15 to September 15, 2026 is 4 whole months.
- Days: September 15 to September 30 is 15 days.
The result is 36y 4m 15d. The same span is 13,287 total days, which divides into 1,898 whole weeks (13,287 ÷ 7 = 1,898.1, rounded down), and 36 × 12 + 4 = 436 total months.
The end date itself is not counted, so on your birthday the day count reads a round number of years with 0 months and 0 days. Because the calculator works with calendar dates only and has no time or time zone field, someone born late at night in another country should first convert the birth moment to their local date with the time zone converter.
Leap Years, February 29, and Month Lengths
Total days are counted from real calendar dates, so every February 29 in the range is included: March 15, 2023 to March 15, 2024 is 366 days because it spans a leap day, while March 15, 2024 to March 15, 2025 is 365 days. Both still show as exactly 1 year.
For someone born on February 29, there is no birthday date in a common year. This calculator treats the year as complete on March 1: born February 29, 2000, the age on February 28, 2001 is 0y 11m 30d, and on March 1, 2001 it is 1y 0m 1d. On the next real leap day, February 29, 2004, the age is exactly 4y 0m 0d. Some jurisdictions legally count a leap-day birthday on February 28 in common years, so check the local rule when age matters for a legal deadline.
Months vary from 28 to 31 days, and the calculator counts months from the start date’s day of the month. When that day does not exist in a shorter month, it uses the last day of that month instead. From January 31 to February 28, 2023 is 0 months and 28 days; one day later, January 31 to March 1, 2023, becomes 1 month and 1 day.
Age Calculation Examples
| Start date | End date | Result | Total days | Total weeks | Total months |
|---|---|---|---|---|---|
| May 15, 1990 | Sep 30, 2026 | 36y 4m 15d | 13,287 | 1,898 | 436 |
| Oct 10, 1995 | Sep 30, 2026 | 30y 11m 20d | 11,313 | 1,616 | 371 |
| Feb 29, 2000 | Feb 28, 2001 | 0y 11m 30d | 365 | 52 | 11 |
| Feb 29, 2000 | Mar 1, 2001 | 1y 0m 1d | 366 | 52 | 12 |
| Sep 30, 2026 | Dec 25, 2026 | 0y 2m 25d | 86 | 12 | 2 |
The last row is a countdown: set the start date to today and the end date to an upcoming event to see how long remains. Expecting parents can estimate the date to count toward with the due date calculator, and developers who need the same moment as a Unix time can use the timestamp converter.
Common uses
- Finding your exact age for a form, application, or eligibility rule
- Getting an accurate age in years to enter into health tools such as the calorie calculator, which uses age in its estimate
- Checking how old someone will be on a future date, such as a school cutoff or retirement date
- Measuring the length of an employment period, tenancy, or project in years, months, and days
- Counting how many days, weeks, or months old a baby is
- Working out the time since or until an anniversary or other milestone
For money, work, and everyday date math, browse the full set of free online calculators.
Age calculator terms explained
| Term | What it means here |
|---|---|
| Chronological age | The time elapsed since birth, measured in calendar years, months, and days; what this calculator shows |
| Exact age | Age stated down to the day, such as 36 years, 4 months, and 15 days, rather than just whole years |
| Total days | The number of calendar days from the start date to the end date, not counting the end date itself |
| Total weeks | Total days divided by seven and rounded down to whole weeks |
| Total months | Whole years multiplied by 12, plus the remaining whole months |
| Leap day | February 29, which exists only in leap years such as 2000, 2024, and 2028 |
Frequently Asked Questions
Enter your date of birth and leave the end date on today. The calculator counts whole years, then whole months, then the remaining days. Someone born on May 15, 1990 is 36 years, 4 months, and 15 days old on September 30, 2026.
Read the Total Days card after entering your birth date. It counts every calendar day from your birth date up to today, including leap days. A birth date of May 15, 1990 gives 13,287 days on September 30, 2026.
The Total Weeks card shows total days divided by seven, rounded down, and the Months card shows whole years times 12 plus the remaining months. For a May 15, 1990 birth date on September 30, 2026, that is 1,898 weeks and 436 months.
Yes. It works from real calendar dates rather than dividing by 365, so every February 29 in the range is counted in the total days and month lengths from 28 to 31 days are handled automatically.
In a non-leap year there is no February 29, so this calculator treats the birthday year as complete on March 1. Born February 29, 2000, the result on February 28, 2001 is 0 years, 11 months, 30 days, and on March 1, 2001 it is 1 year, 0 months, 1 day. Some legal systems count the birthday on February 28 instead, so check local rules for official purposes.
Yes. The first field accepts any start date, not only a birth date, and the end date can be any past or future date. The result is the time elapsed between them in years, months, days, and totals.
Yes. Change the To Date field to the future date, such as a retirement date or an application deadline, and the calculator shows the exact age on that day.
No. The end date is not included, which is the normal way to count age: on the day you were born you are 0 days old, and on your first birthday you are exactly 1 year old.
The birth date picker will not let you pick a date after the end date, and if the dates still end up reversed the calculator swaps them, so the result is always a positive duration.
Months are counted from the start date’s day of the month. From January 31 to February 28, 2023 is 0 months and 28 days, because February has no 31st; from January 31 to March 1, 2023 is 1 month and 1 day.
No. It works with dates only and shows years, months, days, total days, total weeks, and total months. To count the days until your next birthday, set the To Date to that birthday and read the Total Days card.
No. The calculation runs in your browser as you pick the dates. Nothing is uploaded, and no account is needed.
Reviewed by Raja Jahangir · Last reviewed: September 30, 2026
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<iframe src="https://www.thetoolskit.co/embed/age-calculator" width="100%" height="500" style="border:1px solid #ddd;border-radius:12px;" title="Age Calculator" loading="lazy"></iframe> <p style="font-size:13px">Calculator by <a href="https://www.thetoolskit.co/age-calculator">The Tools Kit</a></p>
How do you calculate your exact age?
Your exact age is the difference between your date of birth and today, counted in whole years first, then remaining months, then remaining days. Leap years are handled by counting calendar dates rather than dividing total days by 365, which otherwise drifts by a day every four years.