Age calculations follow standard Gregorian calendar rules and legal conventions. For official legal or immigration purposes (age verification, eligibility), always confirm with the issuing authority — this tool is for personal and planning use only.
Skip to age calculatorEnter your date of birth to calculate your exact chronological age in years, months, and days. Set a reference date for past or future ages, see your next birthday, life statistics, and compare two birth dates—all processed locally with no sign-up.
An age calculator computes the exact elapsed time between a birth date and a target date—returning years, months, days, total days lived, and often a next-birthday countdown.
An age calculator determines the precise elapsed time between a birth date and a reference date. Instead of guessing years from memory or doing fragile mental math, you enter two dates and receive a structured breakdown: completed years, months, and days, plus optional totals such as days lived, hours elapsed, and a next-birthday countdown.
Chronological age—the kind asked on forms, passports, and school enrollment—is not simply “current year minus birth year.” Calendar age only advances on your birthday anniversary. If your birthday has not occurred yet this year, you are still one year younger than the number people sometimes assume. A dedicated DOB age calculator applies the same borrowing rules accountants and government systems use: when the day count would go negative, it borrows from the previous month; when months go negative, it borrows from the previous year.
This page also supports a reference date that defaults to today but can be any past or future day. That single feature answers three common questions at once: how old am I now, how old was I on a historical date, and how old will I be on a future milestone. Quick presets jump the reference date to your next birthday, January 1 of next year, or five or ten years ahead—useful for retirement planning sketches, eligibility checks, and classroom demonstrations.
Beyond personal age, these tools verify minimum-age thresholds, compare two people's birth dates in an age-difference mode, and supply life statistics for curiosity or education. Heartbeat and breath estimates are clearly labeled approximations based on average resting rates—not medical measurements.
All math runs locally in your browser. Birth dates, reference dates, and share links are not uploaded to EverydayTools servers.
Calendar age = completed years, months, and days since birth; total days lived counts every calendar day including leap days.
Concise answers for common searches — definitions, steps, and comparisons.
A leap year adds February 29 to the calendar. Without leap-day handling, age tools would drift for people born on Feb 29, and total-days counts would miss the extra day in leap years. This calculator counts leap years lived and advances Feb 29 birthdays to Feb 28 in non-leap years so countdowns stay predictable.
Start with the year difference between reference date and birth date. If the reference month/day is before the birth month/day, subtract one year. Then compute month difference, borrowing twelve months if needed. Finally compute day difference, borrowing the length of the previous month if the reference day is smaller than the birth day. Total elapsed days is the floor of (reference − birth) in milliseconds divided by 86,400,000.
Personal how-old-am-I checks, school and visa forms, minimum-age verification (18/21), genealogy and historical biography, milestone planning (next birthday, 10,000 days), and comparing ages between siblings or colleagues.
Leap-day births use Feb 28 as the next anniversary in non-leap years on this page. Year counts match either convention; only the anniversary day differs by one day for borderline legal checks.
Calendar age counts completed years, months, and days since each birthday. Total elapsed days is every calendar day between birth and target—including extra leap days.
Enter birth date, set the target date (not today), and read years/months/days as of that moment—useful for legal eligibility, genealogy, and planning.
Select your birth date in the date picker. The calculator accepts standard YYYY-MM-DD input.
Leave empty for today, or pick any past or future date. Use quick presets for next birthday, start of next year, or five or ten years from now.
See primary years/months/days, secondary totals, next-birthday card, and life statistics including optional heartbeat and breath estimates.
Use the Age Difference tab for two birth dates, or copy/share a link that restores your calculation for others.
Common real-world scenarios where this tool saves time.
Everyone
Get years, months, days, and total days lived from your birth date with a live next-birthday countdown.
Students & parents
Verify exact age in years and days for school forms, visa paperwork, insurance, and legal contracts.
HR & compliance
Check whether someone meets 18, 21, or other thresholds as of today or a specific eligibility date.
Researchers
Calculate how old a person was on a historical event date for biographies and family history.
Step-by-step chains that connect related tools for common tasks.
Chain date tools when a project needs more than calendar age.
Find out how old you will be on a specific future date — useful for retirement planning, milestone events, and eligibility checks.
Find the exact countdown to your upcoming birthday in days, hours, and minutes.
Input
Birth date: March 15, 1990 · Target date: May 2, 2026Output
Age: 36 years, 1 month, 17 days · Total days lived: 13,197The calculator counts full years first (36), then remaining months (1), then remaining days (17) after the last monthly anniversary.
Input
Birth date: May 3, 2008 · Target date: May 2, 2026Output
Age: 17 years, 11 months, 29 days — not yet 18The 18th birthday is May 3, 2026. On May 2, the person is still 17 years old—one day short of the threshold.
Input
Birth date: April 15, 1452 · Target date: August 2, 1519Output
Age at death: 67 years, 3 months, 17 daysWorks for any historical dates—useful for biographical research and genealogy.
Age is computed by subtracting the birth date from the reference date in calendar order—years first, then months, then days—borrowing days from the prior month when needed. Total elapsed time is also expressed as days, hours, minutes, and seconds from the millisecond difference.
Formula
years = ref.year − birth.year (adjusted); months and days borrowed when ref day < birth day; totalDays = floor((ref − birth) ÷ 86,400,000 ms)Two ways to measure elapsed time since birth.
| Measure | What it shows | Typical use |
|---|---|---|
| Years, months, days | Calendar age since last birthday | How old am I? |
| Total days lived | Raw day count including leap days | Milestones (10,000 days), research |
| Next birthday countdown | Days until upcoming birthday | Planning and reminders |
When to use this page vs other EverydayTools calculators.
| Tool | Output | Best for |
|---|---|---|
| Age Calculator | Years, months, days from birth date | How old am I, legal age checks |
| Date Calculator | Add or subtract days from a date | Deadline and due-date math |
| Pet Age Calculator | Dog/cat years to human years | Pet life stage estimates |
| Age on Other Planets | Age by planetary orbital years | Fun science comparisons |
| Related tool | Use this tool when | Use related tool when |
|---|---|---|
| Date Calculator | You want to know how old someone is, or how many years/months/days have passed since a birth date. | You want to add or subtract a specific number of days from a date, or calculate the gap between two non-birth-date dates. |
| Age on Other Planets | You need your standard Earth age in years, months, and days for forms, documents, or personal tracking. | You want to see your age expressed in planetary orbital years — a fun science comparison showing how many Jupiter or Mars years you have lived. |
| Birthday Calculator | You want a complete breakdown of time lived: years, months, days, hours, minutes, weekdays, and next birthday countdown. | You want to find out what notable events happened on your birthday, or explore birthday statistics and fun facts. |
Eligibility often depends on age as of a specific day—not necessarily today. Set the reference date to the contract signing date, election day, or event date for an accurate snapshot.
Years/months/days match how humans describe age; total days lived is better for scientific milestones (10,000-day celebrations) or research intervals.
The copy button formats “X Years, Y Months, Z Days” for forms. Share links restore your dates so family members see the same numbers without error-prone manual entry.
Sibling gaps, mentor/mentee age spreads, and genealogy timelines are clearer when you see the exact year-month-day gap rather than rounding to whole years.
Calendar age only advances on your birthday. If today is before your birthday in the current year, you are still one year younger than the upcoming age.
Total days lived is a raw count of calendar days. Years/months/days follow birthday anniversaries—both are correct for different purposes.
Leap-day births use Feb 28 or Mar 1 in non-leap years. Year counts still match; only the anniversary day differs by one day.
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Enter your date of birth and leave the reference date as today—or pick any past or future date. The calculator returns years, months, and days using standard calendar borrowing rules.
Yes. Leap years and February 29 birthdays are handled. In non-leap years, Feb 29 anniversaries use Feb 28 for next-birthday calculations on this page.
Yes. Change the reference date to any future day to see how old you will be on that date—useful for planning milestones or eligibility.
Total days lived appears in Life Statistics and the secondary metrics grid—every calendar day from birth through your reference date.
Switch to the Age Difference tab, enter two birth dates, and see the gap in years, months, and days between the older and younger person.
It uses Gregorian calendar arithmetic—the same method used on forms and documents. For official legal verification, confirm with issuing authorities.
If your birthday has not occurred yet this calendar year, the calculator shows your current age (one year less than the upcoming age). For example, if today is March 1 and your birthday is April 15, you are still one year younger than after April 15.
Yes. Results include years, months, and remaining days, plus total days, weeks, hours, and minutes lived.
Yes. Enter the birth date and today's date (or the eligibility date). If years show 18 or more and the birthday has passed on that date, the person has reached that threshold in most jurisdictions—confirm local rules for edge cases.
No. Age math runs locally in your browser. Your birth date and target date are not sent to EverydayTools servers.
Yes—use Share result to copy a link that restores your birth and target dates. Recipients open the same calculation without retyping dates.
The 'Born on a...' weekday display appears in the Life Statistics section after you enter your birth date. It uses the Zeller/Gregorian formula to compute the day of the week for any historical date. For example, someone born on March 15, 1990 was born on a Thursday.
The Life Statistics panel includes a weekdays-lived count calculated by subtracting weekend days from total elapsed days. The count assumes Gregorian calendar weeks (Monday–Friday = weekdays, Saturday–Sunday = weekend). Exact counts vary slightly around any date with a non-integer week-length remainder.
People born on February 29 only have a true anniversary every four years. This calculator uses February 28 as the anniversary in non-leap years, which is the most common legal convention in the US and UK. Year counts are not affected — a person born on Feb 29, 1992 is counted as turning 34 in 2026 regardless of which day the tool marks as the exact anniversary.
Traditional Korean age adds one at birth and increments on New Year's Day, so it is typically reference year minus birth year plus one. South Korea uses international (chronological) age for most legal purposes since 2023. This calculator shows both your completed international years and the traditional count side by side.
Yes. After you enter a birth date, the Birth profile section shows your Western sun sign, Chinese zodiac animal (calendar year approximation), and generational cohort label such as Millennial or Gen Z.
Day milestones mark round counts of days lived—1,000, 5,000, 10,000, and beyond. The Milestones panel shows your most recent passed milestone and the next upcoming one, with celebration alerts when a milestone was recent or is within seven days.
Yes. Use the Print button to open a clean summary in a new window formatted for printing or saving as PDF through your browser.
Age calculations and dates you enter stay in your browser for normal use—they are not uploaded to EverydayTools servers.
Uses Gregorian calendar rules including leap years; Feb 29 conventions may follow local legal rules.
For personal and planning use—not legal, medical, or official identity verification.
Part of Date & Time Tools
More free tools for the same workflow.
Free age on other planets calculator — find your age on Mars, Venus, Mercury, Jupiter, Saturn, Uranus, Neptune, and Pluto based on each planet's orbital period. No signup. Runs locally in your browser when supported—no upload required for normal use.
Free time calculator — add or subtract hours, minutes, and seconds, or calculate the exact duration between two times. Handles overnight spans automatically. No signup required. Runs locally in your browser when supported—no upload required for normal use.
Add or subtract days, weeks, months, or years from any date. Days-between mode included. No upload—runs locally in your browser. Free, no signup.
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Reviewed by EverydayTools Editorial Team on 2026-06-02.
Exact age calculator
Years, months, days, next birthday, and age difference—100% in your browser.
Pick a date of birth and optionally a reference date to see years, months, days, next birthday, and life statistics—all calculated locally in your browser.