Age Calculator
Calculate your exact age, days until birthday, and discover interesting facts about your birth date
Calculate Your Age
Enter your birth date above to calculate your exact age, see interesting statistics, and find out when your next birthday is.
About the Age Calculator
Age is more complicated than a single number. Depending on the context you might need your age in completed years, the total number of days you have been alive, or the days remaining until your next birthday.
This calculator works those out at the same time, along with conventional date facts such as your zodiac sign and the day of the week you were born.
How to use it
- 1Enter your date of birth.
- 2Optionally set a second date to calculate your age as it will be on that day, rather than today.
- 3Review the results: exact age in years, months and days, total days, hours and minutes lived, and a countdown to your next birthday.
- 4Download a PDF summary if you want to keep the figures.
When you would use it
- Working out an exact age in years, months and days for a form that asks for one.
- Counting the days remaining until a birthday, an anniversary or a deadline.
- Calculating age at a specific past or future date, which is the figure some applications actually require.
How it works, and what it does not do
The calculation runs in your browser and counts calendar units rather than dividing a number of days. Years and months are counted first, then the leftover days, with month lengths and leap days taken from the real calendar for the range you selected. That is why the answer matches what a person would say out loud, where dividing total days by 365.25 would quietly disagree every few years.
Its only dependency is the device clock, which supplies “today”. If the system date is wrong, the result will be wrong in exactly the same way — so on a machine with a mis-set clock, use the specific-date mode and enter the reference date explicitly.
Frequently asked questions
How is the exact age calculated?
By calendar arithmetic rather than simple division. The difference is taken in years, then months, then days, accounting for the varying length of months and for leap years — which is why it can differ from dividing the total number of days by 365.25.
I was born on 29 February — how does that work?
In non-leap years, birthday-based calculations will typically treat 28 February or 1 March as the anniversary depending on the convention used. The exact age in years, months and days remains correct regardless, since it is computed from the calendar difference rather than a fixed anniversary date.
How is my zodiac sign determined?
From the month and day of your birth against the standard Western zodiac date ranges. Note that these ranges shift by a day from year to year, and that traditional sidereal astrology uses different boundaries entirely.
Why does “current age” differ from the age at a specific date?
They measure different intervals. The first is measured to today; the second is measured to the date you choose. A form asking for your age at a particular point in time means the second one.
Does it take leap years into account?
Yes. Month lengths and leap days come from the calendar for the actual range rather than from an average month or year, so totals are exact instead of approximate.