Age Calculator
How to use
Calculates exact age in years, months and days (plus total days) from a birthdate to today. Enter a birthdate and the full breakdown appears.
Date of Birth
- Checking eligibility for an age-restricted service, license, or scholarship
- Calculating a child's exact age in months for pediatric or developmental milestones
- Filling out a form that requires precise age rather than just birth year
- Finding out exactly how many days old you or someone else is
Why two correct age calculations can disagree
Age looks like subtraction and is not. The question "how many years old is someone born on 29 February 2000, on 28 February 2025" has no single right answer, and different legal systems disagree. Most jurisdictions treat the birthday as occurring on 28 February in common years, but some treat it as 1 March. This calculator uses calendar-month arithmetic (it advances the year, then checks whether the month and day have been reached) which matches the common convention and the one almost every form and database uses.
The second source of disagreement is time zones. A birth at 23:30 on 5 June in Mumbai happened at 18:00 on 5 June in London but 13:00 on the same day in New York, and a birth at 00:30 crosses the date line entirely, so the recorded birth date depends on where it was recorded. This tool works in your device's local time zone with whole dates, which is the right behaviour for the question people actually ask. If you need an exact elapsed duration across zones rather than an age, the timestamp converter is the tool for that, because it deals in instants rather than calendar days.
Duration in days is the one figure that is unambiguous, and it is often more useful than years and months. Notice periods, medical intervals and contractual deadlines are almost always specified in days precisely because months vary in length: "three months from 31 January" has no obvious meaning, while "ninety days" has exactly one. When a date calculation carries legal or financial weight, check which convention the other party is applying before you rely on any tool's answer, including this one.
Free and private. Everything runs on your own device, with no account and no uploads.
Figuring out someone's exact age in years, months and days, not just years, comes up more often than you'd expect, from forms to eligibility checks. This tool calculates it.
Yes, the calculation correctly handles leap years when computing exact days and the year/month/day breakdown.
The tool calculates age up to today by default; adjust your "to" date if a specific reference date option is available.
It is commonly used for eligibility rules, milestone tracking, or just satisfying curiosity about exact lifespan in days.
- 1
Enter a birthdate
Type or pick the date of birth.
- 2
View the full breakdown
See exact age in years, months and days, plus total days.
- 3
Use the result
Copy the figures for forms, eligibility checks or curiosity.
- ·Use the exact total-days figure, not just years, when a form or eligibility rule specifies a precise cutoff.
- ·Double check the reference date if you need age as of a past or future date rather than today.
- ·For legal or medical eligibility checks, verify the result against the specific authority's own date rules, since some count age differently around birthdays.