Find your exact age in seconds
Enter your date of birth to see your exact age, days until your next birthday, and your zodiac sign.
Zodiac sign date ranges
The standard Western zodiac date ranges used to calculate your sign.
| Sign | Date range |
|---|---|
| ♑ Capricorn | Dec 22 – Jan 19 |
| ♒ Aquarius | Jan 20 – Feb 18 |
| ♓ Pisces | Feb 19 – Mar 20 |
| ♈ Aries | Mar 21 – Apr 19 |
| ♉ Taurus | Apr 20 – May 20 |
| ♊ Gemini | May 21 – Jun 20 |
| ♋ Cancer | Jun 21 – Jul 22 |
| ♌ Leo | Jul 23 – Aug 22 |
| ♍ Virgo | Aug 23 – Sep 22 |
| ♎ Libra | Sep 23 – Oct 22 |
| ♏ Scorpio | Oct 23 – Nov 21 |
| ♐ Sagittarius | Nov 22 – Dec 21 |
Want your exact age too? Use the birthday calculator above.
About the birthday calculator
This calculator works out your exact age — down to the year, month, and day — from any date of birth, compared against today or any other reference date you choose. Instead of the rough "I'm 34" most people give when asked, it tells you precisely how many years, months, and days you've been alive, plus the total number of days lived since birth.
It also answers a few questions people ask more often than you'd think: how many days are left until your next birthday, which day of the week you were born on, and your Western zodiac sign based on your birth month and day. All of these are calculated instantly as you type, with no sign-up and no data leaving your browser.
Counting age precisely is more fiddly than it looks, because calendar months don't all have the same number of days. Simply subtracting years doesn't account for whether your birthday has already happened this year, and subtracting months can produce a negative day count if the current date falls earlier in the month than your birth date. This calculator handles that "borrowing" the same way you'd do long subtraction by hand — borrowing a month's worth of days when needed, and a year's worth of months when needed — so the years, months, and days you see always add up correctly.
Birthdays have been marked as significant dates for thousands of years. Ancient Egyptians are believed to have celebrated the "birthdays" of pharaohs as divine rulers, while the Greeks linked birth dates to guardian spirits and lit candles on cakes as offerings. Many of the customs still around today — cakes, candles, and even the birthday song — trace back through centuries of overlapping European traditions rather than any single origin.
Zodiac signs, meanwhile, come from a much older system: Western (tropical) astrology divides the year into twelve roughly month-long segments based on the sun's apparent position relative to the constellations at the time the system was standardized in antiquity. This calculator uses the commonly cited date ranges for each of the twelve signs, which is why the cutoff between two signs usually falls between the 18th and 23rd of a month rather than on a fixed day.
Because this tool works in both directions, you can also use it to answer the reverse question: given a target date and a specific age, when would someone need to have been born? Just adjust the reference date to the date you care about — a future event, an eligibility deadline, or a historical date — and the age shown will update for that day instead of today.
Sample ages by birth year
How old you'd be this year, by birth year.
By birth year
Birthday calculator questions
How age, birthdays, and zodiac signs are calculated.
How do I calculate my exact age?
Enter your date of birth and leave the reference date set to today. The calculator subtracts your birth date from today's date, borrowing a month or year where needed, to give you a precise years/months/days breakdown along with total days lived.
Why does my age in years not match a simple subtraction?
Subtracting birth year from the current year only works if your birthday has already happened this year. If it hasn't, you're actually a year younger than that simple subtraction suggests — this calculator accounts for that automatically.
How many days old am I?
This calculator shows your total days lived as one of its results — the exact number of days between your date of birth and the reference date, calculated to the day.
How many days until my next birthday?
The calculator finds the next occurrence of your birth month and day from the reference date — this year's if it hasn't happened yet, or next year's if it has — and counts the days remaining.
How do I find out what day of the week I was born on?
Enter your date of birth and the calculator will tell you the weekday it fell on, using the standard Gregorian calendar.
How accurate is the zodiac sign shown here?
It uses the standard Western (tropical) zodiac date ranges that most horoscope calendars use. Because the exact cutoff date between two signs can vary slightly by source (usually by a day), if your birthday falls right on a boundary it's worth double-checking against your specific date.
Can I calculate someone's age on a future or past date instead of today?
Yes — change the reference date to any date you like. The age, days-lived, and days-until-birthday results will all recalculate as if that date were "today."
Does this calculator account for leap years?
Yes. Because the calculation works directly with real calendar dates rather than a fixed 365-day year, leap years (and the extra day in February) are automatically factored into every result.