Age Calculator by Date of Birth

Calculate your exact age from your date of birth in years, months and days. Find how old you are today or on a specific past or future date, with a live age clock and next-birthday countdown.

Calculate Your Exact Age from Date of Birth

Enter your date of birth below. Leave the optional target date blank for your live age, or choose a date to check how old you were or will be.

Date of birth

Use Day / Month / Year, or pick a date from the calendar. To paste, use 24/08/2006 or 2006-08-24.

About This Exact Age Calculator

This age calculator by date of birth answers “How old am I today?” with your age in completed years, months and days. You can also check a past or future date, view your age in smaller units and count down to your next birthday. Use it for your own age or the chronological age of a child or baby.

How to calculate age from date of birth

Enter your date of birth (DOB) in the separate Day, Month and Year boxes, or use the calendar picker. Select Calculate My Life to see your result. For example, with birth time left blank, someone born on 15 June 2000 is 26 years, 3 months and 0 days old on 15 September 2026.

The labelled boxes work for both UK and US visitors. Pasted dates use day/month/year, such as 24/08/2006, or year-month-day, such as 2006-08-24. A pasted date is not read as US month/day/year; use the labelled fields or calendar if you usually write dates that way.

Calculate age on a specific date

Open Calculate age on to find how old you were on a past date or how old you will be at a future birthday, anniversary or event. Leave those fields blank to return to your current age.

A selected target date uses 12:00 AM at the start of that day in your browser’s local time zone. It must not be earlier than your entered birth date and time. The age totals and birthday countdown then refer to that fixed date rather than updating live. To find a date a set number of days ahead first, use our days from now calculator.

Age in years, months, days and smaller units

The main result shows calendar years, months and remaining days. Your life in totals shows completed months and total weeks, days, hours, minutes and seconds. These are different views of the same time span:

  • Completed months: the years in your result multiplied by 12, plus the remaining completed months. This is useful when expressing a baby’s or child’s age in months.
  • Total days and weeks: whole elapsed 24-hour periods and whole seven-day weeks, rounded down. The days in the main result are only the remainder after years and months.
  • Hours, minutes and seconds: whole elapsed units since the birth date and optional birth time. The current-age result updates every second while the page is active.

For a duration you already know in days, use the days converter to explore other units. Its approximate months and years can differ from a calendar age based on two dates.

How chronological age and leap years are calculated

Chronological age measures the calendar time since birth. This calculator counts completed years, then advances through months and remaining days. It uses actual month lengths and leap years. When a year or month step would land beyond the end of a shorter month, it uses that month’s last valid day.

For 29 February birthdays, anniversary calculations use 28 February in non-leap years. Elapsed totals use time differences, so daylight-saving changes can make a local calendar day differ from a full 24-hour period. The result is general calendar age; it does not determine legal eligibility, provide clinical age assessment or serve as official proof of age.

Birth time, next birthday and day-of-birth details

Open Add birth time for more precision to enter an hour in 24-hour format and a minute. Blank time fields use midnight. Entering a time changes the elapsed totals and can affect completed years, months or days before that time is reached. Dates use your browser’s local time zone; there is no separate birthplace or time-zone conversion.

The birthday calculator shows the next birthday date, a countdown in days, hours, minutes and seconds, and progress through the current age year. With birth time entered, the countdown runs to that time. You can also find the weekday you were born and milestones such as 10,000 days or one billion seconds alive.

Age on other planets, zodiac and generation

Explore approximate planetary years from Mercury to Neptune, plus the Moon’s lunar cycles. These conversions use orbital periods and do not change your age on Earth. Extra cards show a Western zodiac sign, a birthstone, a numerology life-path number and a generation label based on birth year. Generation boundaries vary between sources; the Chinese zodiac estimate uses the Gregorian year and may differ for January or early-February births. Personality descriptions and body/lifetime estimates are for entertainment.

Private age calculation in your browser

The calculator processes your entered birth date and time in your browser without submitting them to a server or saving them for a later visit. After calculating, you can copy a summary or download an image or PDF. Those files are saved only when you choose a download. Normal website resources and the PDF library may still load from external servers.

Frequently Asked Questions Age Calculator FAQs

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

Enter your day, month and four-digit birth year, then select Calculate My Life. The result shows completed calendar years, months and days, plus totals in smaller units. Leave Calculate age on blank for the current date and time, or enter a target date to check your age then.

How old am I today?

Enter your date of birth and leave the optional target date blank. Your age appears in years, months and days, with a live hours, minutes and seconds clock. Add your birth hour and minute if known; otherwise the calculator counts from midnight on your birth date.

Can I calculate my age on a specific past or future date?

Yes. Open Calculate age on and enter the date you want to check. The result uses midnight at the start of that day in your browser’s local time zone and stays fixed. The target must not be earlier than your birth date and time; a same-day target will be too early if you enter a birth time after midnight.

What is chronological age?

Chronological age is the calendar time that has passed since birth, usually expressed in years, months and days. It is different from biological age or a health assessment. This tool provides general calendar age; for an official application, follow the organisation’s required reference date and calculation rules.

Can I use this as an age calculator for a child or baby?

Yes. Enter the child’s date of birth just as you would an adult’s. The results include calendar age, completed months and total weeks and days. These are chronological-age figures; the calculator does not adjust for premature birth or decide school-entry or medical eligibility.

How many days old am I?

Calculate your age, then find Total days under Your life in totals. It counts complete 24-hour periods since your birth date and optional birth time. The smaller day figure in the main age result is the remainder after completed years and months, so it is not your total days old.

Can I calculate my age in months, weeks, hours, minutes and seconds?

Yes. Your life in totals includes completed months and total elapsed weeks, days, hours, minutes and seconds, rounded down to whole units. Completed months come from your calendar years and months, not an average month length. Live mode updates the figures every second; a selected target date gives a fixed result.

Does entering my birth time make the calculation more precise?

Yes. Enter your birth hour and minute to count from that time instead of midnight. This changes the live clock and elapsed totals, and can affect completed age units before your entered time is reached. Birth seconds are assumed to be zero. The calculator uses your browser’s local time zone and does not convert from a birthplace time zone.

Does the calculator handle leap years and 29 February birthdays?

Yes. Date validation checks real month lengths, including whether February has 28 or 29 days. For a 29 February birth, anniversary calculations and the birthday countdown use 28 February in a non-leap year. If an official age threshold depends on a leap-day birthday, check the relevant authority’s rule.

How many days are left until my next birthday?

See Your birthday countdown for the remaining days, hours, minutes and seconds, plus your next birthday’s date. It counts down to your entered birth time, or midnight if time is blank. The countdown updates in live mode; with a target date selected, it shows the time remaining from that date.

Can I find the day of the week I was born?

Yes. Enter a valid birth date and look under Day of birth & generation. The result shows the weekday on which your date of birth fell, alongside a generation label based on your birth year. You do not need to enter a birth time to find the weekday.

Can I see my age on other planets?

Yes. The results show approximate planetary years for Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, using elapsed Earth days and each planet’s orbital period. The Moon result shows lunar cycles. These are astronomical conversions for interest, not changes to your chronological age.

Does the calculator show my zodiac sign, birthstone and generation?

Yes. It shows a Western zodiac sign, an estimated Chinese zodiac sign, a birthstone, a numerology life-path number and a birth-year generation label. The Chinese zodiac estimate uses the Gregorian year, so January and early-February birthdays may differ under the Lunar New Year calendar. Generation boundaries vary, and personality descriptions are for entertainment.

What date format should I use in the UK or US?

Use the separate Day, Month and Year boxes or the calendar picker. When pasting, use DD/MM/YYYY, such as 24/08/2006, or YYYY-MM-DD, such as 2006-08-24. The tool does not interpret pasted dates as US MM/DD/YYYY; for August 24, enter Day 24 and Month 08.

Is my date of birth stored or sent to a server?

The calculator keeps your entered dates and birth time in the current browser page to perform the calculation. It does not submit them to a server or save them for later visits. The website can still load normal resources, including an external PDF library when needed. A downloaded result contains the birth details shown in that export.

Can I download or copy my age result?

Yes. After calculating, use Copy summary, Download image or Download PDF. The copied text includes your calendar age and generation; the image and PDF contain a broader age summary. You can save these for personal reference or share them, but they are not official proof of age.

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