Calculators

Age Calculator

Enter your date of birth to find your exact age in years, months and days, plus your next birthday and more.

Date of birth
Optional

Your age

–years
–months
–days

Enter your date of birth to see your exact age.

Next birthday

– days to go

–

Your countdown appears here.

Last birthday
–
Half birthday
–
Year of life
–

Your age in…

Months
–
Weeks
–
Days
–
Hours
–
Minutes
–
Seconds
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You were born on a

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Enter a date of birth.

Star sign
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Chinese zodiac
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Generation
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Fun facts

Estimates
  • –heartbeats
  • –breaths
  • –hours asleep
  • –full moons

Rough averages, not measurements. How we estimate these

How the age calculator works

Enter your date of birth as a day, month and year, or pick it from the calendar. The age calculator counts the complete years since you were born, then the complete months since your last birthday, then the days left over. That’s exactly how you would work out an age by hand, minus the slips. Results update as you type.

Alongside your age you’ll see your next birthday with a countdown, your age in months, weeks, days, hours, minutes and seconds (the seconds tick live), the day of the week you were born, your star sign, your Chinese zodiac sign and generation, and a few fun estimates.

Options for more precise answers

  • Age on a different date. Change Age on to any past or future date to see how old you were or will be then. It’s handy for forms that ask your age on a specific date, or for working out someone’s age at a historical event.
  • Time of birth. Add it to make the hours, minutes and seconds exact. It doesn’t change your age in years, months and days: you turn a year older at the start of your birthday, whatever time you were born.
  • Date format. The fields follow your browser’s usual order (day/month/year or month/day/year). Switch it with the format menu above the fields.
  • Share or save. Every result has its own link, so you can bookmark it or send it with Copy result or Share.

Edge cases, handled properly

  • Leap years. February has 29 days every fourth year, except in century years not divisible by 400. So 2000 was a leap year, but 1900 wasn’t.
  • Birthdays on 29 February. In common years there is no 29 February, so by default your birthday is counted on 28 February. Some people and some laws use 1 March instead, and you can choose whenever you enter a 29 February birth date.
  • Birthdays at the end of a month. If you were born on the 31st, your monthly birthday in a shorter month falls on its last day. Born on 31 January? You’re one month older on 28 February (29 February in a leap year).
  • Time zones and daylight saving. Dates are compared as calendar dates in your own time zone, so a clock change can never make you a day older or younger.
  • Old dates. Any date from the year 1 to 9999 works, using the Gregorian calendar throughout.

Every rule is written out, with examples, in our methodology.

Your date of birth stays on your device. The calculator runs entirely in your browser; nothing you type is sent to us or stored on a server. The date appears in the page address only so you can bookmark or share a result.

How to calculate your age manually

You can work out an exact age with nothing more than a calendar. Write both dates as day, month and year, then:

  1. Count the full years. Subtract the birth year from the current year. If the birthday hasn’t come round yet this year, subtract one.
  2. Count the full months. Count the whole months from the last birthday up to the current month. If today’s day of the month is earlier than the birth day, the current month isn’t complete, so subtract one.
  3. Count the remaining days. Count the days from the most recent monthly birthday (the same day number as the birth date) up to today.

Worked example

Say you were born on 14 August 1995 and today is 29 October 2026.

  • Years: 2026 − 1995 = 31, and 14 August has already passed this year, so that’s 31 full years.
  • Months: from 14 August to 14 October 2026 is 2 full months. 14 November hasn’t arrived yet.
  • Days: from 14 October to 29 October is 15 days.
  1. 14 August 1995Date of birth
  2. + 31 years 14 August 2026
  3. + 2 months 14 October 2026
  4. + 15 days 29 October 2026
Age: 31 years, 2 months and 15 days. In total that’s 11,399 days.

Example: born at the end of a month

Born on 31 January 2000, how old is someone on 28 February 2001? One full year takes us to 31 January 2001. February 2001 has no 31st, so the next monthly birthday falls on its last day, 28 February. The answer is exactly 1 year and 1 month, with no days left over.

A calculator that mechanically borrows days from the previous month may say 1 year, 0 months and 28 days instead. Both conventions are in use, and we explain the difference in why age calculators sometimes disagree.

Example: born on 29 February

Born on 29 February 2004, how old is someone on 28 February 2025? 2025 isn’t a leap year. If the birthday is counted on 28 February, that day is their birthday and the answer is 21 years. If it’s counted on 1 March, the answer is 20 years, 11 months and 30 days, one day short. Our guide to leap day birthdays covers the rules in detail, and the step-by-step guide to calculating age has more practice examples.

What people use an age calculator for

Knowing your age in years is easy. Knowing it exactly, or on a particular date, is where a calculator helps:

  • Forms and applications. Passport, visa, insurance, pension and job forms sometimes ask for your age on a specific date rather than today.
  • School and sports cut-offs. Check whether a child meets an age rule on a cut-off date. For assessments that need age in years and months, use the chronological age calculator.
  • Milestones. Find the day you turn 10,000 days old with the age in days calculator, or browse other age milestones.
  • Family history. Enter a birth date and set Age on to a date of death to find someone’s age when they died.
  • Planning ahead. See how old you’ll be on a future date, or how long you have until retirement age.
  • Birthdays. Count down to the big day with the birthday countdown, or compare two people with the age difference calculator.

Frequently asked questions

How do I calculate my age from my date of birth?

Subtract your birth year from the current year, then subtract one more if you haven’t had your birthday yet this year. That gives your age in completed years. For months and days, count the full months since your last birthday, then the days since your most recent “monthly birthday”. The calculator above does all of this instantly, leap years included.

How old will I be on a certain date?

Enter your date of birth, then change Age on to the date you have in mind. The calculator shows your exact age on that day, past or future, and counts down from it to your next birthday.

How is age calculated if I was born on 29 February?

In leap years you celebrate on 29 February as normal. In other years there’s no 29 February, so this calculator counts your birthday on 28 February by default, which keeps it in February. Some people, and some legal systems, use 1 March instead; when you enter a 29 February birth date you can switch between the two. Our guide to leap day birthdays explains the rules.

Why does it say one month when only 28 days have passed?

That happens when you were born at the end of a month. If you were born on 31 January, your next monthly birthday is the last day of February, because February has no 31st. So on 28 February you’re exactly one month older, even though only 28 days have passed.

Does my time of birth change my age?

Not in years, months and days. You turn a year older at the start of your birthday, whatever time you were born. The time of birth only makes the hours, minutes and seconds exact.

How many days old am I?

Enter your date of birth and look under Your age in…: it shows your age in days, along with months, weeks, hours, minutes and seconds. For upcoming day-count milestones, try the age in days calculator.

Is my date of birth stored or shared?

No. Everything is calculated in your browser and nothing you type is sent to our servers. Your date of birth appears in the page address only so that you can bookmark or share the result. See our privacy policy.

Why do different age calculators give different answers?

Usually because they handle month ends and leap days differently, or count the end date differently. A few use other age systems altogether, such as traditional Korean age. We go through each difference in why age calculators sometimes disagree.

Can I find someone’s age at death?

Yes. Enter their date of birth, then set Age on to the date they died. The result is their exact age at death.

Does the calculator work for dates before 1900?

Yes. It accepts any date from the year 1 to 9999 and applies today’s Gregorian calendar rules throughout. Many countries used the older Julian calendar until the 1700s or later, so a historical date recorded in that calendar needs converting first for a precise answer.

More age and date calculators

Each one is built for a specific question, with the same careful date handling.

Guides

Plain-English explanations of how age is counted, and why the details matter.