Age Calculator
Find your exact age in years, months and days from your date of birth – plus your next birthday, your age in weeks, days and seconds, and the age gap between two people.
- Instant results
- Age on any date
- Age difference
- Runs in your browser
Calculated on your device. Dates are never uploaded or saved.
Enter a date of birth
Your exact age, next birthday and milestones will appear here instantly.
How to use the age calculator
- Enter the date of birthType the day and year and choose the month. Your age appears instantly as you type.
- Pick the date to measure toKeep “Today”, or choose “Another date” to find the age on an exam cut-off, a past event or a future date.
- Read and share the resultSee years, months and days, the next birthday and milestones, then copy the result or a link to it.
How your age is calculated
Age is counted in completed units, the same way it is written on forms. The calculator first counts the full years since the date of birth, then the full months since the last birthday, and finally the days left over.
Worked example: born on 12 May 1998, measured on 18 March 2024. The 25th birthday was on 12 May 2023, so that is 25 years. From 12 May 2023 to 12 March 2024 is 10 months. From 12 March to 18 March is 6 days. The age is 25 years, 10 months and 6 days.
Month ends and leap years
Because months have 28 to 31 days, a date like 31 January has no match in February. When that happens the calculator uses the last day of the shorter month, so one month after 31 January is 28 February (29 February in a leap year). People born on 29 February are treated as having their birthday on 28 February in common years. Some legal systems use 1 March instead, so check the rule that applies to you when it matters.
Age in other units
| Unit | How it is counted |
|---|---|
| Months | Completed calendar months since birth, plus remaining days |
| Weeks | Total days divided by 7, plus remaining days |
| Days | Exact number of calendar days, including every leap day |
| Hours, minutes, seconds | Counted from midnight on the date of birth; live when measuring to today |
Doing it in a spreadsheet
In Excel or Google Sheets, with the date of birth in cell A2, =DATEDIF(A2, TODAY(), "Y") gives completed years and =DATEDIF(A2, TODAY(), "YM") gives the extra months. Microsoft documents that the "MD" option can return incorrect day counts, which is a common source of off-by-one errors.
When an exact age matters
Many rules set an age limit “as on” a fixed date rather than today: school and college admissions, competitive exams, government and private job applications, sports age groups, insurance and pension eligibility. Choose Another date and enter the cut-off date from the official notice to see the age exactly as the rule measures it.
Use the Age difference tab to compare two birth dates – for siblings, couples, or checking a gap required by a form. For decisions with legal or financial consequences, always confirm against the official rule and the original birth record.
Frequently asked questions
How do I calculate my exact age?
Enter your date of birth and keep “Today” selected. The calculator counts the completed years since you were born, then the completed months since your last birthday, then the remaining days. For example, someone born on 12 May 1998 is 25 years, 10 months and 6 days old on 18 March 2024.
How do I find someone’s age on a specific date?
Choose “Another date” under “Calculate age on” and pick the date. This is how you check an age limit that is measured “as on” a cut-off date, such as a school admission, an exam or a job application.
How is age calculated for someone born on 29 February?
In leap years the birthday is 29 February. In common years this calculator treats 28 February as the birthday, so a person born on 29 February 2000 turns 1 on 28 February 2001. Some laws and organisations use 1 March instead, so check the rule that applies to you.
Why do some age calculators show a different number of days?
Months have different lengths, so calculators must decide how to count from a date like 31 January. This calculator moves to the last day of a shorter month (31 January plus one month is 28 or 29 February) and then counts the remaining days. The total number of days lived is always the same.
How do I calculate the age difference between two people?
Switch to the “Age difference” tab and enter both birth dates. You will see who is older and the exact gap in years, months and days, as well as in total months, weeks and days.
How many days old am I?
Enter your date of birth and look at “Your age in other units”. It shows your age in days, weeks and months, and counts hours, minutes and seconds live from midnight on your birth date.
Can I calculate age in Excel or Google Sheets?
Yes. With the birth date in cell A2, =DATEDIF(A2, TODAY(), "Y") returns completed years and "YM" returns the extra months. Microsoft notes that the "MD" option can give wrong results in some cases, so check day counts with a calculator like this one.
Is my date of birth stored or sent anywhere?
No. The calculation runs entirely in your browser. Dates are not saved or sent to our servers. A link to your result is only created if you click “Copy link”.
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