Make sense
of your time.
Your exact age. Your next birthday. The days between two moments. Get a clear answer, with the calculation explained.
How old are you, exactly?
Use today or choose another reference date.
Your dates & details
Calendar calculationReady when you are
Enter your dates and select Calculate.
Dates, birthdays & beyond.
Exact age calculator
Years, months and days on any date.
Calendar ageAge difference calculator
Compare two birth dates in either order.
Compare datesBirthday countdown
Find your next birthday and save the date.
Birthday planningDate difference calculator
Count elapsed days or include both dates.
Calendar daysAdd or subtract a date
Move a date by years, months, weeks or days.
Date planningBirthday milestone calculator
Find the date of your 18th, 50th or any birthday.
Birthday planningTraditional Korean age
Compare traditional, international and year age.
Cultural countingCat age in human years
A sourced, approximate age comparison for cats.
Pet comparisonDog age in human years
A chart comparison for medium-sized dogs.
Pet comparisonOne answer down.
What’s next?
Count a draft, calculate a percentage, convert a measurement or create a password. Explore the main MultipleTools collection.
Browse all tools ↗A few minutes, more clarity.
How to calculate age in years, months and days
A clear method for counting completed years, calendar months and the remaining days.
Why month-end age calculations go wrong
Understand short months, leap days and the convention used in our calculations.
Count down to your birthday and save the date
Set a reference date, choose a leap-day rule and download a calendar event.
Before you calculate
Does this include leap years?
Yes. Calendar dates use Gregorian leap-year rules. For 29 February birthdays, choose either 28 February or 1 March as the anniversary in a non-leap year.
Can I calculate age on a different date?
Yes. Change the reference date in the age calculator to any supported date on or after the birth date.
Is my birth date saved?
Your entries are used in this browser for the calculation. The supplied website does not store them in a database or browser storage. Copying or exporting a result creates a copy under your control.
Why can two tools show different month counts?
Calendar months have unequal lengths. Our tools count forward through completed years and months, clamping unavailable month-end days. The calculation guide explains that convention.
Can I use the pet comparison to judge health?
The comparison is approximate and uses a general chart. Ask your veterinarian about the needs of an individual animal.