25 free birthday and age tools
Your birthday, worked out to the second.
Enter your date of birth once and see your exact age, the weekday you were born, your zodiac sign, birthstone, generation and the countdown to your next birthday.
Every birthday tool, in one place
Each tool explains exactly how it calculates, with worked examples.
Your exact age, the days and weeks you have lived, and how ages compare: for forms, milestones, school tests and couples.
Age Calculator
Your exact age in years, months, days and seconds.
Age and timeHow Many Days Old Am I
Your age in days, plus the date of your 10,000th day.
Age and timeLife in Weeks
Your whole life as a grid of weeks, ready to print.
Age and timeAge Difference Calculator
The exact gap between two birthdays.
Age and timeRetirement Countdown
Years, months and working days until you retire.
Age and timeAge on Other Planets
How old you would be on Mars, Jupiter and beyond.
Age and timeChronological Age Calculator
Age on a test date in years, months and days, the way test manuals count it.
The dates worth celebrating: your next birthday, a live countdown, your half birthday and golden birthday, and the weekday you were born.
Days Until My Birthday
A quick answer, down to the second.
Birthday datesBirthday Countdown
A full-screen party countdown to share or embed.
Birthday datesGolden Birthday Calculator
The year you turn the age of the day you were born.
Birthday datesHalf Birthday Calculator
Six months from your birthday, plus your half birthday twins.
Birthday datesWhat Day Was I Born
The weekday you were born and what the rhyme says about it.
How common your birthday is and how many people share it, from 21 years of US birth records, the odds of a shared birthday in a group, and the generation your birth year belongs to.
How Rare Is My Birthday
Where your birthday ranks among all 366 days, from US birth records.
Birthday dataBirthday Twin Finder
How many people share your birthday, and the odds of meeting one.
Birthday dataWhat Generation Am I
Boomer, Gen X, Millennial, Gen Z or Gen Alpha.
Birthday dataBirthday Paradox Calculator
The chance that two people in a group share a birthday.
Your Western and Chinese zodiac signs, life path and lucky numbers, and a fun compatibility score. These are for entertainment.
Zodiac Sign Calculator
Your sun sign, element and traits.
Zodiac and numerologyChinese Zodiac Calculator
Your animal and element, using the Lunar New Year date.
Zodiac and numerologyLife Path Number Calculator
Reduce your birth date to one number, with every step shown.
Zodiac and numerologyLucky Number Calculator
Numbers drawn from your birth date, with the method shown.
Zodiac and numerologyBirthday Compatibility Calculator
A match score for two birthdays.
The traditional birthstone and birth flowers for each month, with their colors and meanings.
Never miss a date: a birthday calendar for your family, class or office that prints on one page and adds to your phone's calendar, and an anniversary calculator for how long you have been together.
Birthday Calendar
Keep family, class or office birthdays in one calendar.
PlannersAnniversary Calculator
Time together, the next milestone and the gift for each year.
Planning an anniversary gift? Anniversary Gifts by Year lists the traditional and modern gift for every year, from paper to diamond.
Birthday facts from 21 years of US birth records
From 85.7 million US births, 1994 to 2014 (CDC and Social Security data).
- The most common birthday is September 9. September holds 9 of the 10 most common dates. Nine months before mid-September is the December holiday season.
- The rarest birthday is February 29, which comes only in leap years. After it come December 25, January 1 and December 24: the rarest dates are holidays or the days around them.
- September is the busiest month, with about 11,811 births a day, and January the quietest, with about 10,721.
- Tuesday is the most common weekday to be born (16.4% of births) and Sunday the least (9.8%). Planned deliveries tend to fall on working days.
See where your own birthday ranks with How Rare Is My Birthday, or browse every date on the most and least common birthdays page.
Why people trust the answers
Exact to the day
Leap years, month lengths and your local time zone are all handled. Every tool shows the rule it uses.
Your date stays with you
Calculations run in your browser. BdayChecker does not store the birth dates you enter.
Sources you can check
Data tools name their source, such as US birth records from the CDC and the Social Security Administration.
BdayChecker questions
Is BdayChecker free?
Yes. Every tool is free to use, with no sign-up and no limit on how often you use it.
Do I need my birth year?
Only for tools that work out an age. Days until your birthday, the countdown, half birthdays, birthday twins, birthday rarity and zodiac signs work with the month and day, and the birthstone and birth flower tools need only the month.
Is my birth date saved?
No. The tools work in your browser and the dates you enter are not sent to us. A date only appears in a web address if you copy a share link, and the Birthday Calendar keeps its list in your own browser.
Where do the birth numbers come from?
From CDC and Social Security data: every US birth from 1994 to 2014, counted for each calendar date. The rarity, birthday twin and weekday tools use it.
Does it work outside the US?
Yes. Ages, countdowns and dates work for any birthday, in your own time zone, on the Gregorian calendar. The birth statistics are from the US, and the pages say so where they are used.
How are the tools checked?
Each tool shows the rule it uses, with worked examples, and every fact is checked against its source before it is published. Pages show the date they were published and last updated.