Determine the age or interval between two dates in years, months, weeks, days, hours, minutes, and seconds.
This calculator uses the most common age system where age increases on a person's birthday. Some cultures count age differently — including or excluding the current year.
In the traditional Chinese system, people are born at age 1 and gain a year on Chinese New Year, not their actual birthday.
Month and day results can sometimes be confusing when the starting date is at the end of a month.
The Babylonians and Egyptians developed calendars over 5,000 years ago to track time and age, making age calculation one of humanity's oldest practices.
In East Asian cultures (Chinese, Japanese, Korean), a baby is considered 1 year old at birth and gains a year on New Year's Day rather than on their actual birthday.
In the Western system, age starts at 0 and increases by 1 on each birthday. A person is "n years old" after the nth anniversary of their birth.
The oldest verified person ever was Jeanne Calment of France — 122 years and 164 days (1875–1997).
Global average life expectancy has nearly doubled over 200 years — from about 35–40 years in the early 1800s to 72–73 years today, thanks to advances in medicine, nutrition, and sanitation.
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