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Age Calculator

Calculate exact age in years, months, and days.

Ever wondered exactly how many days, hours, or even minutes you have been alive? Our free Age Calculator computes your exact age in years, months, weeks, days, hours, and minutes from your date of birth to today. You can also calculate the time between any two dates, making it useful for anniversaries, deadlines, and countdowns.

Simply enter your date of birth using the date picker. The calculator uses today date as the end date by default. For custom date ranges (such as a project duration or how long ago an event happened), enable the "Custom end date" option and pick any past or future date.

The result panel shows your age in multiple formats simultaneously: years + months + days (the standard way people express age), total months lived, total weeks, total days, total hours, and total minutes. For future dates, the calculator shows the countdown to that date.

Our calculator accounts for leap years correctly and uses the actual number of days in each month rather than approximating. The difference algorithm is based on widely accepted date arithmetic used by libraries like date-fns and moment.js.

Frequently Asked Questions

How does the calculator handle leap days?
Leap years are fully accounted for. The actual number of days between two dates is calculated using JavaScript Date objects, which internally represent time as milliseconds since the Unix epoch and correctly handle all calendar quirks including leap years.
Why does "months" sometimes show different values?
A month is not a fixed number of days — it ranges from 28 to 31. The year/month/day result borrows from the next larger unit when necessary, similar to how you would manually count anniversaries. For example, Jan 31 to Mar 1 is "1 month and 1 day" (counting Feb 28/29 as the month boundary).
Can I use this to calculate a due date or countdown?
Absolutely. Set the start date to today and the end date to the future event date. The result shows how many months, weeks, and days remain, plus total days/hours/minutes until that date.
What is the earliest date I can calculate from?
JavaScript Date objects reliably support dates from approximately 100 million days before the Unix epoch (271,821 BCE) to 100 million days after (275,760 CE). In practice, Gregorian calendar dates before 1582 should be treated with historical caution.

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