Calculate your exact age in years, months and days from your date of birth. Also shows total days lived, your next birthday countdown, and age on any chosen date.
Enter your date of birth to get your exact age in years, months and days, along with total days lived, your next birthday countdown, and the day of the week you were born. Change the second date to find your age at any past or future point.
Calendar arithmetic has no clean unit. Months vary from 28 to 31 days, and years from 365 to 366. Dividing elapsed days by 365.25 gets you close but produces answers that disagree with how anyone actually counts age.
The correct method subtracts each component separately and borrows when necessary. If the day-of-month difference is negative, you borrow the length of the preceding month; if the month difference is then negative, you borrow twelve months from the year. This is what produces an answer that matches your intuition and your legal age.
Date-only values are a common source of off-by-one bugs. In JavaScript, new Date("1995-06-15") is parsed as UTC midnight, but getDate() reads it in local time - so anyone west of Greenwich sees June 14. This calculator works entirely in UTC, so the result is stable wherever you are.
Enter your date of birth
Use the date picker or type the date directly.
Set the target date
Defaults to today. Change it to calculate age at any past or future date, or click Today to reset.
Read the breakdown
See exact years, months and days, plus totals in months, weeks, days and hours.
Forms and applications
Get an exact age for official paperwork, school enrolment or medical forms.
Eligibility checks
Confirm whether someone meets an age threshold on a specific future date.
Milestone planning
Count down to a birthday or work out the date of a 10,000-day milestone.
Genealogy
Calculate how old an ancestor was on a historical date from records.
Age is counted in complete calendar units, not by dividing days by 365. The calculator subtracts the birth year, month and day from the target date, borrowing from the previous month when the day is negative. This is the same method used for legal age.
Leap years are handled correctly because the calculation works on real calendar dates rather than a fixed year length. If you were born on February 29, most jurisdictions treat March 1 as your legal birthday in non-leap years, though the calculator will show the exact calendar difference.
Because roughly one year in four has 366 days. Over 30 years you accumulate about 7 extra days from leap years. Counting actual elapsed days is the accurate approach and is what this tool does.
Yes. Change the second date to any value. This is useful for checking eligibility ages, retirement dates, or how old someone was on a specific historical date.
All calculations run in UTC to avoid off-by-one-day errors that occur when local timezones and daylight saving shifts are applied to date-only values. Your result will be the same regardless of where you are.