Age Calculator

How old are you, exactly? Most of us can say our age in years without thinking, but the exact figure in years, months and days, or the total number of days we have lived, is harder to work out by hand. Leap years, months of different lengths and the date of your last birthday all get in the way. This Age Calculator does the counting for you. Enter your date of birth, and it gives your age in years, months and days, plus the total days, weeks and months, and the time until your next birthday.

It is free, works on any device and gives its answer at once. You can use your own birth date or work out someone else’s age, and you can choose a reference date so you can find out how old someone was, or will be, on any date. The rest of this page explains the tool, shows a worked example and answers the questions people ask most.

What Is an Age Calculator?

An Age Calculator is an online tool that works out a person’s age from their date of birth. Instead of counting years by hand, the tool compares the birth date with a reference date, usually today, and breaks the gap into whole years, whole months and days. It also totals the time in months, weeks and days, and tells you how long remains until the next birthday.

The result is a clear breakdown you can use for forms, for checking eligibility, for school enrolment, for retirement planning and for simple curiosity. Because the tool uses real calendar dates, it handles leap years and months of different lengths correctly, which is exactly where counting by hand goes wrong.

How to Use the Age Calculator

Use it in four steps:

1. Enter your date of birth in the first field, in dd/mm/yyyy format, or use the date picker to choose it from the calendar.
2. Optionally, enter a reference date in the second field. Leave it blank and the calculator uses today’s date automatically.
3. Click the “Calculate Age” button. The result appears at once: “Your Age Is: 36 years, 9 months, 25 days”, with the breakdown below it.
4. Click “Reset” if you want to clear the fields and start again.

The reference date is the useful part many people miss. Set it to a past date to find out how old you were on that day, or to a future date to find out how old you will be then. You can also use the buttons below the result to copy the result, share it or download it.

How the Calculator Works

The tool works out the time between the date of birth and the reference date in three parts. First it counts whole years, then whole months, then the remaining days. For a birth date of 15 January 1990 and 8 November 2026, that is 36 whole years to 15 January 2026, then 9 whole months to 15 October 2026, then the days after that.

It also totals the same time in months, weeks and days: months is the total number of months, weeks is the total days divided by 7, and total days is the full day count. All of it is based on real calendar dates, so leap years are included and months are not averaged.

One detail is worth knowing: the tool counts the days inclusively, including the current day. That is why the total days figure for 15 January 1990 to 8 November 2026 is 13,447, one more than a strict count of the days that have passed, which would be 13,446. The same inclusive count gives 25 days instead of 24 in the years, months and days breakdown, and it shows the next birthday as 14 January 2027 instead of 15 January. The figures on this page are the tool’s own figures, so use them as shown.

Worked Example

Take a date of birth of 15 January 1990, with the reference date left blank, so the calculator uses today, 8 November 2026.

The tool gives: “Your Age Is: 36 years, 9 months, 25 days”. The breakdown is: Years 36, Months 9, Days 25, Weeks 1,921, Total days 13,447, and Next birthday in 67 days (14/01/2027).

Checking the breakdown: 15 January 1990 to 15 January 2026 is 36 years. 15 January 2026 to 15 October 2026 is 9 months. The remaining days run to 8 November, which the tool counts as 25 days. The total days figure, 13,447, is exactly 1,921 weeks, so the weeks figure matches the days figure. Enter 15 January 1990 into the tool and it gives exactly these figures.

Reading the Results

The headline result is the age in years, months and days, which is the form most people need. Below it, the rows give the same age in other units: Months is the total number of months, Days is the days part of the breakdown, Weeks is the total time in weeks, and Total days is the full day count. The last line tells you how many days remain until your next birthday, with the date it falls on, which is handy for planning.

Remember that this tool does not show hours, minutes or seconds, only years, months, days, weeks and the total days. If you need a time of day, that detail is not part of this calculator.

When to Use It

• When you are filling in a form that asks for your exact age.
• When you are checking eligibility for school, work, a licence or a pension, where the exact age on a given date matters.
• When you are planning a milestone birthday and want to know how old someone will be on a future date, using the reference date field.
• When you want to compare two ages, which the Age Difference Calculator works out.
• When you need the gap between any two dates, not just birthdays, which the Date Difference Calculator finds.
• When you want to count days, for example, how many days remain until an event, which the Days Calculator works out.

Tips for Accurate Results

Enter the date of birth in the right order: day, then month, then year. Double-check the year, since a single mistyped digit changes the answer by years, not days. If you are working out an age on a specific date, set the reference date to that date instead of trusting today’s date. Note the inclusive day count, so expect the total days to be one more than a strict elapsed-days count. And no data is stored or shared: the calculation happens in your browser, and the tool keeps no record of what you enter.

Frequently Asked Questions

1. How does the calculator handle leap years?

It uses real calendar dates, so leap years are included in the count. A person born on 29 February still gets a correct age, and the total days figure includes every leap day that has passed.

2. Why is the total days figure one more than a days-between calculation?

Because the tool counts days inclusively, including the current day. For 15 January 1990 to 8 November 2026 it gives 13,447 days, while a strict count of the days that have passed gives 13,446. The same rule gives 25 days instead of 24 in the breakdown, and shows the next birthday a day earlier than the calendar date.

3. Can I work out my age on a future date?

Yes. Enter the future date in the reference date field and the calculator works out your age on that date. Leave the field blank to use today.

4. What does “Next birthday in 67 days” mean?

It is the countdown to your next birthday from the reference date, with the birthday shown beside it. For a birth date of 15 January 1990 and today, 8 November 2026, the tool shows 67 days to 14/01/2027, using its inclusive day count.

5. Does the calculator store my date of birth?

No. Nothing is stored or shared, and there is no account to create. The calculation runs in your browser.

6. Is this calculator free, and does it work on a phone?

Yes. It is completely free to use, with no sign-up, and it works in a browser on phones, tablets and desktop computers.

Disclaimer

Disclaimer: This Age Calculator provides estimated results based on standard formulas and should be used for general informational and educational purposes only. While it aims for accuracy, results may vary slightly due to leap years, time zones, and calendar variations.