🎂 Age

Age Calculator

Find the exact age between any two dates in years, months and days — plus total days, weeks, hours and a countdown to the next birthday. Press Calculate.

Written and reviewed by SM Arijul Islam · Last reviewed 20 October 2026 · Editorial standards · Report an error

How age is calculated

Age is the calendar distance between two dates, not simply a division of days by 365. This calculator counts complete years first, then complete months, then the remaining days, so 29 February birthdays and differing month lengths are handled correctly.

Also calculated

Total days, weeks, hours and minutes lived
The weekday you were born on
Days remaining until your next birthday
The date of your next birthday

For durations, try the Date Calculator. For future financial dates, the Loan Calculator shows a full payoff schedule.

Worked example

Someone born on 15 March 1990 has, on 19 October 2026, an age of 36 years, 7 months and 4 days. The calculator counts whole years first, then whole calendar months, then the leftover days, so the parts always add up to the real elapsed time rather than an average year.

Everyday uses

Filling in forms that ask for an exact age
Checking eligibility for visas, pensions or benefits
Working out age gaps between people or events
Converting a date of birth into months for a child's record
Counting exactly how many days old you are

Frequently asked questions

How exactly is age calculated?

Whole years first, then whole calendar months, then the remaining days — using the real calendar rather than a fixed 365-day year.

Why do leap years matter?

They add an extra day every four years, so dividing a day count by 365 drifts away from the true age over time.

Is age in months just years × 12?

No. Months vary between 28 and 31 days, so the calculator counts real calendar months instead of multiplying.

Can I use it for a future date?

Yes. Enter a future date and the result shows the time remaining, which is handy for deadlines and countdowns.

More worked examples

Someone born on 1 January 2000 turns 26 on 1 January 2026, and is 26 years 9 months 18 days on 19 October 2026.
That same person has lived 9,788 days by 19 October 2026, once the seven leap days between 2000 and 2025 are counted.
A 30-year-old has lived roughly 10,957 days, because 30 multiplied by the average 365.2425-day year gives that figure.
A leap-day birthday of 29 February is treated as 1 March in non-leap years by most legal systems.

Units of age

Common age periods and their equivalents
Period	Equivalent
1 year	365 days, or 366 in a leap year
1 month	30.4369 days on average
1 fortnight	14 days
1 decade	10 years
1 score	20 years
1 millennium	1,000 years

Common mistakes to avoid

Counting the day of birth as day one. Age starts at zero, so a baby is not one year old until the first anniversary.
Forgetting leap days when converting years to days. Each four-year block holds one extra day.
Dividing total days by 30 to get months. Months range from 28 to 31 days, so the result drifts by several months over a lifetime.
Confusing current age with the age someone will be on their next birthday, which is one year higher.

Further questions

What does chronological age mean?

Simply the time elapsed since birth, which is what this calculator measures. It is distinct from biological or developmental age.

How is age handled for a 29 February birthday?

Most legal systems treat 1 March as the anniversary in common years, though a few use 28 February. Check the rule where it matters.

Why is my age in months not just my days divided by 30?

Because calendar months vary between 28 and 31 days. A year of 365 days is 12 months, not 12.17 months.

Does the time of day or timezone matter?

It can. Someone born near midnight can be counted as a day older or younger depending on which timezone the record uses.

Korean age, add days to date and working days

The Korean age calculator uses the traditional counting system: a baby is one at birth and gains a year every 1 January, so Korean age = current year − birth year + 1. South Korea abolished that system for official documents in June 2023, so most people now also have an international age, which is the exact age shown above.

To add days to date, pick a start date and count forward, remembering that weekends and month lengths change the weekday. For a working days calculator, count Monday to Friday between two dates and exclude public holidays yourself — a plain working-day count does not know your country's calendar.

Days added to a date and weekdays they land on
From	Plus 30 days	Plus 90 days
1 January	31 January	1 April (or 31 March in a leap year)
1 April	1 May	30 June
1 July	31 July	29 September
1 October	31 October	30 December