How this age calculator works
Working out an exact age sounds simple, but months have different lengths and leap years add an extra day, so mental maths often goes wrong by a day or two. This calculator counts the full years first, then the full months, and then the remaining days, borrowing days from the previous month when needed, exactly as you would on paper. It also counts the total number of days between the two dates, so you can see how many days, weeks and hours you have been alive. You can change the "age on date" field to any past or future date, which is handy for forms that ask your age as on a specific cut-off date.
Age on a specific date: exam and job forms
Government recruitment notices, school admissions and competitive exams often set an age limit "as on" a particular date, such as 1 January or 1 August of the exam year. If the rules say candidates must be between 18 and 27 years old as on 1 August, set the second date to 1 August and check the result in years, months and days. Being one day over the limit can make an application invalid, so always confirm the exact cut-off date and any relaxations (for reserved categories, for example) in the official notice.
Worked example
Someone born on 15 January 2000 is, on 3 November 2026, 26 years, 9 months and 19 days old. They have been alive for 9,789 days, which is about 1,398 weeks or roughly 235,000 hours. Their next birthday on 15 January 2027 is 73 days away. Their Western zodiac sign is Capricorn, and their Chinese zodiac animal is usually given as the Rabbit, because Chinese New Year 2000 fell on 5 February, so a mid-January birth belongs to the previous lunar year (1999, Rabbit) rather than 2000, the year of the Dragon.
Leap year birthdays
If you were born on 29 February, your birthday appears on the calendar only once every four years. Legally and socially, people celebrate on 28 February or 1 March in common years; the rule differs between countries. This calculator treats 1 March as the next birthday in non-leap years and still counts your age correctly in years, months and days.
Your zodiac sign and Chinese zodiac animal
The calculator shows your Western (tropical) Sun sign, based on the usual date ranges: Aries from about 21 March, Taurus from 20 April and so on. The exact change-over time varies by a day from year to year, so if you were born on a cusp date, check a full birth chart. It also shows your Chinese zodiac animal, which follows a 12-year cycle: Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog and Pig. The Chinese year starts at the lunar new year, which falls between 21 January and 20 February, so if you were born in January or early February your animal may belong to the previous year. The page reminds you when that applies.
Fun facts about your age
- Your 10,000th day falls a little after your 27th birthday (around 27 years, 4 months), a milestone some people celebrate.
- A "half birthday" is six months after your birthday.
- In traditional Korean and some East Asian counting, a baby was counted as one year old at birth; South Korea officially adopted international age counting in 2023.
- The number of days alive grows by 365 each year, or 366 when a 29 February passes.
Privacy
Your birth date is processed entirely in your browser. Nothing is sent to a server, stored or shared, and the page uses no cookies or analytics.
Different ways to express age
Doctors and paediatricians often give a baby's age in weeks and then months up to about two years, because development milestones change quickly. Insurance companies sometimes use "age nearest birthday" or "age last birthday", which can differ by a year for the same person. Most legal documents use completed years, which is what the first line of the result shows. If a form is unclear, use completed years and check the instructions.
Calculate the age difference between two people
You can also use this tool to find the gap between two people: enter the older person's birth date as the date of birth and the younger person's birth date as the second date. The result shows the exact difference in years, months and days.
See what the stars say for your sign today on Zodiac Sign For Today.
Frequently asked questions
How do I calculate my exact age?
Count full years, then full months, then remaining days between your birth date and today. The calculator does it automatically, including leap years.
How many days old am I?
Enter your date of birth; the result shows total days alive, plus weeks and hours.
How do I calculate age as on a specific date?
Change the "age on date" field to the cut-off date in your form, such as 1 January or 1 August.
How is age calculated for someone born on 29 February?
They age normally; in non-leap years this calculator uses 1 March as the next birthday.
What is my Chinese zodiac animal?
It follows a 12-year cycle starting at the lunar new year. If you were born in January or early February, check whether your birth was before that year's new year.
When will I be 10,000 days old?
A little after your 27th birthday, at about 27 years and 4 months.
Is my date of birth stored?
No. Everything is calculated in your browser and nothing is saved.