Age Calculator
Calculate exact age from a date of birth: years, months and days as of today or any other date, or the total months, weeks or days. Works for historical dates too.
Last updated: October 2026
Age
36 years
Formula below · 1 source (timeanddate.com) · Updated Oct 2026
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About this calculator
Your age in years is the number of birthdays you have had. This calculator counts calendar birthdays and month-days exactly instead of dividing by an average year length, so it is right on the birthday itself and across leap years.
How it counts
Completed years: the target year minus the birth year, minus one if this year's birthday has not happened yet. Years, months and days: whole years first, then whole months since the last birthday, then the days left over. When a later month is too short for your birth day (born on the 31st, say), the month is counted as complete on that month's last day. Total days is the exact number of days between the two dates; total weeks is that number divided by 7.
Example: someone born on June 15, 1990 is 34 years, 3 months and 21 days old on October 6, 2024: 12,532 days in total.
Born on February 29
In common years the calculator treats March 1 as the leap-day birthday, a widely used legal convention. Some places use February 28 instead, so check local rules if the exact day matters for a legal deadline.
Historical dates
Any years from 1 to 9999 work, so you can find the age of a historical figure at a given event. The calculator uses the Gregorian calendar for all dates. Many older records, including British dates before September 1752, use the Julian calendar; convert both dates to the same calendar first or the result can be off by up to about two weeks.
Leave the target date blank to use today's date on your device. Enter only a target year to get the age reached during that year, which is handy when an event's exact date is unknown. In the numeric formats a target date before the birth date gives a negative number, the time remaining until birth.
How to use
Enter the day, month and year of birth. The default birth date, June 15, 1990, shows that person's age today. Leave the three "Age on" boxes blank to get the age as of today, or fill them in to get the age on another date, such as a deadline, an anniversary or a historical event. Choose how to show the result: completed years (the default), years, months and days, or the total number of months, weeks or days. If you only know the year of an event, enter just the year. For example, Napoleon Bonaparte, born August 15, 1769, was 51 years, 8 months and 20 days old when he died on May 5, 1821.
Frequently asked questions
How do I calculate my exact age?
Subtract the birth year from the current year, and subtract one more if your birthday has not come yet this year. For months and days, count the whole months since your last birthday and then the days since the last month-day. The calculator does this for you, including leap years.
How old is someone born on February 29?
They gain a year on February 29 in leap years. In other years the calculator counts the birthday as March 1, a common legal convention; some places use February 28 instead.
How many days old am I?
Choose "Total days" under Show age as. Someone born on June 15, 1990 was 12,532 days old on October 6, 2024.
Can I calculate the age of a historical figure?
Yes. Enter the birth date and the date of the event as the target date. For dates before the Gregorian calendar was adopted in that country, convert both dates to the same calendar first.
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Sources & references
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