Age Calculator

How to Calculate Your Exact Age

Enter your date of birth above and this tool instantly works out your exact age in years, months and days, along with useful totals — total months, weeks, days, hours and even minutes lived. It also shows fun extras like your zodiac sign, Chinese zodiac animal and generation, plus a live countdown to your next birthday.

The Formula Behind the Calculation

Age in years, months and days is found by subtracting your birth date from the target date, component by component. If the target day-of-month is earlier than your birth day-of-month, one month is borrowed and converted into days using the actual number of days in the previous calendar month — which is why the calculator correctly handles months of different lengths and leap years, rather than assuming every month is 30 days.

Worked Example

Someone born on 15 March 1990, checking their age on 29 September 2026, is exactly 36 years, 6 months and 14 days old — that's 13,345 days, or roughly 320,280 hours, since birth.

Frequently Asked Questions

How is my exact age calculated?

We take the number of full years, months and days between your date of birth and the target date. Because months have different lengths, we count backwards from the target date's day-of-month, borrowing days from the previous month when needed — the same way you'd count on a calendar by hand.

Why do total days, weeks, hours and minutes matter?

Years, months and days are the everyday way to describe age, but the totals are useful for milestones — knowing you've been alive 10,000 days, or working out an exact duration for a legal, medical or trivia purpose.

How does the calculator handle a birthday on 29 February?

In years that aren't leap years, a 29 February birthday is treated as falling on 28 February for the purposes of counting the next birthday, which matches how most calendars and government systems handle it.

Is my Chinese zodiac based on my exact birth date?

It's approximated from your Gregorian birth year. The real Chinese lunar new year moves between late January and mid-February each year, so if you were born in that window your traditional sign could differ from the year-based approximation shown here.

Can I calculate someone's age on a date other than today?

Yes — change the "Age at date" field to any date (past or future) to see how old you were, or will be, on that day, along with the days remaining to your next birthday at that point.

Is this age calculator free and private?

Yes. It runs entirely in your browser — your date of birth is never sent to our servers or stored anywhere.