Age Calculator

An exact age is the time elapsed between a birth date and a target date, counted as whole years first, then whole months, then the remaining days. Calculate an exact age, the days between two dates, or a countdown to a future date — in years, months and days, plus the total in weeks, days and hours. Leap years and uneven month lengths are handled.

Age — years, months, days
Total weeks — weeks
Total days — days
Total hours — hours

How to Calculate Exact Age

Two dates, an exact answer.

1

Enter the birth date

Pick the date of birth with the date selector. It can be any past date.

2

Set the target date

Leave it on today for current age, or choose a past or future date to find age on a specific day or a coming birthday.

3

Read the breakdown

See the age in years, months and days, plus total weeks, days and hours. Counting a shift instead of a lifetime? Use the Hours Calculator.

Frequently Asked Questions

How do you calculate your age from your date of birth?
Your age is the number of full years from your date of birth to today: count the years between your birth year and now, then subtract one if this year's birthday has not happened yet. Someone born on 15 March 2000, for example, turns 25 on 15 March 2025 and is 24 until that day. Enter your date of birth above and the calculator shows your exact age in years, months and days, updating for today's date, leap years and the different month lengths automatically.
How does the age calculator handle months of different lengths?
The age calculator uses real calendar months rather than a fixed 30 days. The calculator works out the difference in years, then months, then days, borrowing from the previous calendar month when the day of the target date is earlier than the day of birth. Because it borrows the actual number of days in that month — 28, 29, 30 or 31 — the years-months-days result matches how people naturally count age. This is more accurate than dividing the total days by 30.44, which only gives an average and can be off by a day or two.
Does it account for leap years?
Yes — the age calculator counts leap days. The total-days figure is the true number of calendar days between the two dates, so every February 29 that falls in the span is counted automatically. The years-months-days breakdown also respects leap years because it steps through real calendar months. If you were born on February 29, the calculator counts a completed year on February 28 in common years and on February 29 in leap years, which is the most widely used convention for leap-day birthdays.
Can I calculate age at a past or future date?
Yes — an age can be worked out at any past or future date. The target date defaults to today, but you can set it to any date — past or future — to find how old someone was on a specific day or will be on a coming birthday or event. As long as the target date is on or after the birth date, the calculator returns a valid age. If you accidentally set a birth date later than the target date, it shows a short note instead of a negative age, since you cannot be a negative number of years old.
What are the total weeks, days and hours for?
Alongside the years-months-days age, the calculator shows the same span expressed entirely in weeks, in days and in hours. These are handy for milestones — a baby's age in weeks, a project's age in days, or a fun fact like how many hours old you are. The hours figure assumes midnight as the time of day, since the tool works with dates rather than exact birth times, so it is accurate to the day rather than the minute.
How do I find the number of days between two dates, or until a future date?
Switch the calculator to Days between dates to count the exact number of days from one date to another in either order — it shows the total in days, weeks and hours, plus the gap in years, months and days. Choose Countdown to see how many days are left until a future date such as a birthday, holiday, exam or deadline; it fills in today's date for you and counts down. Every result uses true calendar days, so leap years and the different lengths of each month are already accounted for, and the math runs entirely in your browser as you type.

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