Age Calculator

Find your exact age in years, months, weeks, days, hours, and minutes from your date of birth. Also shows how many days until your next birthday.

Enter dates

How the age calculator works

01
Enter your date of birth
Select your exact date of birth from the date picker. The calculator defaults to a date 25 years ago and today as the target date, so you can see results immediately.
02
Set the target date
This defaults to today but can be changed to any date — useful for calculating how old someone will be on a future date, or how old they were on a past date.
03
View your exact age
Your age is shown in years, months, weeks, days, hours, and minutes. The birthday countdown also shows exactly how many days until your next birthday.

The calculator works by subtracting your date of birth from the target date, accounting for varying month lengths and leap years. The exact breakdown (years, months, days) handles edge cases like birthdays that fall at the end of months correctly.

To find out how old someone will be on a specific future date — such as a retirement date or milestone birthday — simply change the target date field to that date.

How age is calculated

Working out an exact age sounds simple, but it involves more than subtracting one year from another. A precise age depends on the specific day, month, and year of birth compared against today's date, and it has to account for the uneven lengths of months and for leap years. This calculator does that work for you, expressing your age in years, months, weeks, and days from any date of birth.

The method counts complete years first, then complete months, then the remaining days, rather than treating every month as thirty days. That is why your age in months is not simply your age in years multiplied by twelve — it reflects the real calendar. Leap years, which add an extra day every four years to keep the calendar aligned with Earth's orbit, are handled automatically so that a birthday on 29 February is counted correctly.

Why the same age looks different in different units

Expressing an age in days or weeks often produces surprisingly large numbers, because a single year contains 365 or 366 days. Someone who is thirty years old has lived for around eleven thousand days. These alternative units are useful for milestones — a ten-thousand-day birthday, for instance — and for precise calculations such as working out exact ages for forms, eligibility dates, or record-keeping.

Worked example

For example, someone born on 15 June 1990 is, on 26 August 2026, exactly 36 years, 2 months, and 11 days old — not simply 36. Counted another way that is 434 months, or more than 13,200 days. If you are completing a form that needs your exact age on a particular date, enter that target date instead of today and the calculator gives you the precise figure rather than a rounded one.

Frequently asked questions

How are leap years handled?

The calculator accounts for leap years automatically, so ages spanning 29 February and birthdays on that date are counted accurately.

Why isn't my age in months just my years times twelve?

Because months vary in length. The calculator counts complete calendar months and the leftover days, which reflects your true age more precisely than a rough estimate.

Can I calculate age between any two dates?

Yes. Although it is often used with today's date, you can find the exact gap between any birth date and any target date, which is handy for planning or eligibility checks.