Count days, weeks, months and years between two dates, or add and subtract calendar time from a date.
Age Calculator
Find your exact age in years, months and days from your date of birth, plus your age in days, weeks and hours and the days to your next birthday.
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Dates
Pick it from the calendar or type the day, month and year.
Today by default. Change it to see the age on any other date.
Age
Enter a date of birth to see the age.
- Years
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- Months
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- Days
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| Born on | – |
|---|---|
| Total months | – |
| Total weeks | – |
| Total days | – |
| Total hours | – |
| Next birthday | – |
How the age is counted
- Years and months are the complete calendar years and months since the date of birth. Days are counted from the last monthly anniversary, borrowing the days of the previous month when needed.
- If the birth day does not exist in a month (such as the 31st in April), that month’s anniversary is its last day. A 29 February birthday counts on 28 February in non-leap years.
- Total weeks = total days ÷ 7. Total hours = total days × 24, which ignores the time of birth, time zones and daylight-saving changes.
Runs entirely in your browser. Your files and text are not uploaded.
How to use Age Calculator
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Step 1: Enter the date of birth
Pick the date from the calendar, or type the day, month and year.
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Step 2: Check the second date
The age is worked out for today. Change “Calculate age on” to find the age on any other day, past or future.
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Step 3: Read or copy the result
See the age in years, months and days, the totals, the weekday of birth and the next birthday, and copy them in one click.
How the age is calculated
The calculator counts the completed years and months from the date of birth to the chosen date, then the days since the last monthly anniversary of the birth date. This is how age is usually stated on forms. For example, on 16 October 2026 someone born on 15 August 1990 is 36 years, 2 months and 1 day old.
When the day of the month you are counting to is earlier than the birth day, a month is borrowed. From 20 January to 5 March 2026 is 1 month and 13 days: 20 February completes the first month, then there are 8 more days to the end of February and 5 days in March.
Birthdays at the end of a month
Not every month has a 29th, 30th or 31st. When the birth day does not exist in a month, that month's anniversary falls on its last day. Someone born on 31 January turns one month old on 28 February, or on 29 February in a leap year. From 31 January to 1 March is therefore 1 month and 1 day.
People born on 29 February have their birthday counted on 28 February in years that are not leap years, so they turn a year older on that day. Some laws use 1 March instead, so for legal purposes check the rule that applies to you.
Totals in months, weeks, days and hours
- Total days is the number of days from the date of birth to the chosen date. The day of birth itself is not counted, so a baby born yesterday is 1 day old.
- Total weeks is total days ÷ 7, shown as whole weeks and the days left over.
- Total months is the number of completed months and the days since the last one.
- Total hours is total days × 24. It is approximate, because it ignores the time of birth, time zones and daylight-saving changes.
For example, from 15 August 1990 to 16 October 2026 is 13,211 days, which is 1,887 weeks and 2 days, or about 3,17,064 hours.
Next birthday and day of birth
The result also shows the weekday you were born on, the date of your next birthday, how many days are left and the age you will turn. If the chosen date is the birthday itself, it says so.
Age on a specific date
Job and exam notifications often ask for your age "as on" a cut-off date, such as 1 January of the exam year. Enter that date in "Calculate age on" to see your age on that exact day.
The dates you enter stay in your browser and are not sent to our server or saved.
Limitations
- Ages are worked out from calendar dates only. The time of birth, time zones and daylight-saving changes are not taken into account, so total hours are approximate.
- Rules for 29 February birthdays and for age limits on official forms vary. This calculator counts those birthdays on 28 February; check the exact rule if the result matters legally.
- Dates follow the Gregorian calendar used today. Dates from before a country adopted it (Britain switched in 1752) may not match dates written at the time.
- Years must have four digits (1000 to 9999). Ages over 150 years are calculated but flagged, because they are usually typing mistakes.
Frequently asked questions
How do I calculate my age from my date of birth?
Count the full years from your birth date to today, then the full months since your last birthday, then the days since the last monthly anniversary. If today’s day of the month is before your birth day, borrow the days of the previous month. The calculator does this for you, including short months and leap years.
How many days old am I?
Enter your date of birth and leave the second date as today. The “Total days” row shows how many days have passed since you were born. A child who has just turned one is 365 days old, or 366 if a 29 February fell in that year.
How are 29 February birthdays handled?
In leap years the birthday is 29 February. In other years this calculator counts it on 28 February, so someone born on 29 February 2000 turned 1 on 28 February 2001. Some legal systems use 1 March instead.
Can I find my age on a past or future date?
Yes. Change “Calculate age on” to any date after the date of birth, for example the cut-off date in an exam or job notification, or a future date to see how old you will be. Press “Today” to go back to the current date.
Why is the number of hours only approximate?
It is the number of days multiplied by 24. The calculator does not know your time of birth, and it ignores time zones and the hour gained or lost when clocks change for daylight saving.
Is my date of birth saved?
No. The calculation runs in your browser. Nothing you enter is sent to our server or stored.
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