Age Calculator

Age is calculated by breaking down the time between two dates into years, months, and days. The calculator subtracts full years first, then full months from the remainder, then counts the leftover days. This gives you the familiar "32 years, 5 months, and 12 days" format rather than a single large number.

For the total breakdowns (weeks, hours, minutes), the calculator counts the exact number of calendar days between the two dates and multiplies accordingly. A 30-year-old has lived roughly 10,957 days, or about 262,968 hours — numbers that feel surprisingly large because we rarely think in those units.

The Gregorian calendar adds a leap day (29 February) every four years, except for century years that aren't divisible by 400. So 2000 was a leap year, but 1900 was not, and 2100 won't be either. This calculator handles all of these edge cases correctly.

If you were born on 29 February, your birthday only occurs every four years on the calendar. In non-leap years, most countries legally treat 1 March as your birthday — though some jurisdictions use 28 February. This calculator counts your exact age regardless, using the precise number of days elapsed.

Different cultures use different calendars. The Islamic (Hijri) calendar has 354-day years, so someone who is 30 in Gregorian years is about 31 in Hijri years. The Hebrew calendar is lunisolar, the Chinese calendar combines lunar months with a zodiac cycle, and the Ethiopian calendar has 13 months. This calculator uses the international Gregorian standard.

Chronological age is simply the time since birth — what this calculator measures. It's the number on your driving licence and passport.

Biological age reflects how well your body functions compared to the average person of the same chronological age. It's influenced by genetics, diet, exercise, sleep, and stress. A 50-year-old marathon runner may have the biological age of a 38-year-old, while a sedentary 50-year-old might be biologically 60.

Mental (cognitive) age measures intellectual development relative to age norms. Originally designed for children, it compares problem-solving ability, memory, and reasoning to population averages. Vocabulary and general knowledge actually increase well into your 60s, even as processing speed peaks in the late teens.