Age Calculator
Enter a date of birth to see the exact age in years, months and days, plus total days lived and the countdown to the next birthday.
Runs in your browser. Your data is not uploaded.How our tools work
Defaults to today. Change it to find an age on any other date.
How do I calculate my age?
Enter the date of birth and the calculator shows the exact age today in years, months and days. It counts complete years first, then complete months, then the remaining days, and handles leap years and month ends. To check eligibility on a deadline, change “Age on this date”.
- Enter the date of birth.
- You see the age on today’s date first. To find an age on another date, for example an application deadline, change “Age on this date”.
- Read the exact age in years, months and days, plus the totals and the countdown to the next birthday.
Formulas & Methods
Age in years
Example: Born 15 March 2000, on 10 March 2026: 2026 − 2000 − 1 = 25 years
Remaining months and days
Example: From 15 March 2025 to 10 March 2026: 11 months (to 15 February) and 23 days
Key features
Exact years, months and days
Calendar-accurate: month lengths and leap years are handled correctly.
Age on any date
Check how old someone was, or will be, on a specific day, such as an exam cut-off date.
Totals
See the age as total months, weeks and days.
Next birthday
Shows how many days remain until the next birthday and which age it will be.
Day of the week
Find out which weekday the person was born on.
Common uses
- Check age eligibility for exams, jobs, visas or sports categories
- Work out a child’s exact age in months
How age is calculated
The calculator counts complete years first, then complete months, then the remaining days. A month counts as complete when the day of the month reaches the birth day. For example, from 15 March to 14 April is 30 days, and from 15 March to 15 April is exactly one month.
When the birth day doesn’t exist in a month, the last day of that month is used. Someone born on 31 January reaches one month on 28 February (or 29 February in leap years), and someone born on 29 February has their birthday on 28 February in non-leap years.
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Frequently Asked Questions
How is age calculated for people born on 29 February?
In non-leap years this calculator treats 28 February as the birthday. Legal rules differ between countries: some use 1 March instead, so check local rules when an exact legal date matters.
Can I calculate an age on a future date?
Yes. Change “Age on this date” to any future date to see how old someone will be on that day.
Why does the total number of days differ from years × 365?
The total counts the real days between the dates, including every 29 February, so it is slightly more than 365 per year.
How do I check whether someone is under 18 on a deadline?
Set “Age on this date” to the deadline. A result of 17 years and any number of months and days means the person is still under 18 that day; 18 years, 0 months and 0 days means they turn 18 on the deadline itself.
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