Birthday Calculator: Everything About Your Birth Date
This birthday calculator turns one date into a full profile of your birthday. Enter your date of birth and you see your current age, the number of days until your next birthday, the weekday you were born on and the weekday your next birthday falls on. It also lists your zodiac sign, birthstone, Chinese zodiac animal and how common your birthday is in the United States.
to go
- Zodiac sign
- Birthstone
- Chinese zodiac
- How common
Most age tools stop at the number of years, but people searching for a birthday calculator usually want more than that. They want to plan a party, settle a bet about which day of the week they were born, or find out whether a December 25 birthday is as rare as it feels. Every one of those answers comes from the same date, so the tool shows them together.
How to Use the Birthday Calculator
Type your date of birth in month, day and year order, then press Calculate. The birthday calculator returns your age in years, months and days, a live countdown to your next birthday, and the date of your half birthday. Below that are the extra facts tied to your date.
You can also change the reference date to see the countdown from any day, which is useful for planning a surprise ahead of time. If you leave out the birth year, the tool still shows the countdown, zodiac sign and birthstone, since those depend only on the month and day. Your age, generation and weekday of birth need the full date.
Three steps
- 1Enter the birth dateMonth and day are enough. Add the year for age and weekday of birth.
- 2Pick a count from dateLeave it empty for today, or choose a later day to plan a surprise.
- 3Read the profileAge, countdown, weekdays, half birthday, zodiac and rarity together.
Days Until Your Next Birthday
The countdown counts the days from today to the next time your month and day come around. If your birthday was yesterday, the answer is 364 or 365 days, depending on whether a February 29 falls in between. On your birthday itself, the birthday calculator shows zero and a short greeting instead.
People born on February 29 get a countdown to February 28 or March 1 in common years, based on the setting they choose. The tool also shows the next real leap year birthday, which is February 29, 2028. Parents of young children often use the countdown in sleeps instead of days, and the birthday countdown page offers that view.
What Day of the Week Were You Born?
The calculator works out the weekday for any date in the Gregorian calendar, so it can tell you whether you were a Monday or a Sunday baby. It uses the same arithmetic as Zeller’s congruence, a formula published in the 19th century for finding the day of the week. The result also shows the weekday your birthday falls on this year and next year.
Weekdays of birth are not spread evenly in the United States. Fewer babies are born on Saturdays and Sundays because scheduled cesarean deliveries and inductions usually happen on weekdays. Tuesday has often been among the most common birth days in national data.
Weekday of birth facts
Zodiac Sign, Birthstone and Chinese Zodiac
Your Western zodiac sign comes from the month and day, such as Aries for March 21 to April 19 or Capricorn for December 22 to January 19. Your birthstone comes from the month alone, from garnet in January to turquoise in December. Both are matched automatically by the birthday calculator.
The Chinese zodiac animal depends on the birth year and the Lunar New Year, not on January 1. Someone born in January 2000 is a Rabbit, while someone born after February 5, 2000 is a Dragon. The calculator checks the Lunar New Year date for your birth year so the animal is correct even for January and February birthdays.
| Month | Birthstone | Zodiac signs that month |
|---|---|---|
| January | Garnet | Capricorn to Jan 19, then Aquarius |
| February | Amethyst | Aquarius to Feb 18, then Pisces |
| March | Aquamarine | Pisces to Mar 20, then Aries |
| April | Diamond | Aries to Apr 19, then Taurus |
| May | Emerald | Taurus to May 20, then Gemini |
| June | Pearl | Gemini to Jun 20, then Cancer |
| July | Ruby | Cancer to Jul 22, then Leo |
| August | Peridot | Leo to Aug 22, then Virgo |
| September | Sapphire | Virgo to Sep 22, then Libra |
| October | Opal | Libra to Oct 22, then Scorpio |
| November | Topaz | Scorpio to Nov 21, then Sagittarius |
| December | Turquoise | Sagittarius to Dec 21, then Capricorn |
How Common Is Your Birthday?
An analysis of US births from 1994 to 2014, based on Social Security Administration data, found that September 9 was the most common birthday. Mid September dates fill much of the top ten, which lines up with conceptions during the winter holiday season. The least common dates were December 25, January 1, December 24 and July 4, when planned deliveries are rarely scheduled.
February 29 is rare for a different reason: it exists only once every four years. Roughly one in 1,461 people is born on a leap day. Your birthday calculator result shows whether your date ranks as common, average or rare.
Frequently Asked Questions
How many days until my birthday?
Enter your date of birth in the calculator and it counts the days from today to your next birthday. The count updates every day automatically. For a quick estimate, count the full months remaining and multiply by about 30.
What day of the week was I born?
The calculator finds the weekday for your exact date of birth instantly. It uses the Gregorian calendar, which the United States has followed since 1752. You can also check the weekday of any future birthday.
What is the rarest birthday?
February 29 is the rarest birthday because it occurs only in leap years. Among regular dates, December 25 and January 1 are the least common in US data. Holidays see fewer scheduled births.
What is the most common birthday in the United States?
September 9 ranked first in an analysis of US births from 1994 to 2014. Several other mid September dates were close behind. Those births trace back to conceptions around the winter holidays.
What is my Chinese zodiac animal?
Your Chinese zodiac animal depends on your birth year and the date of the Lunar New Year that year. If you were born in January or early February, you may belong to the previous year’s animal. The birthday calculator checks this for you.