Age calculator
Enter a date of birth to see the exact age broken down into years, months, weeks, days, hours, and minutes.
About this tool
Working out an age sounds like subtraction, and mostly is, until the edge cases arrive. Calendar months have different lengths, so there is no fixed number of days in a month to divide by. Leap years insert a day every four years, except in century years not divisible by 400 — 1900 was not a leap year and 2000 was. Someone born on 29 February has a birthday that exists only once every four years, and jurisdictions disagree on whether they legally age on 28 February or 1 March in ordinary years. Age matters legally in more places than people expect: pension and retirement eligibility, insurance premium bands, visa and immigration categories, school admission cut-offs, medical dosing, and statutory age thresholds all turn on an exact figure rather than an approximate one. This calculator takes a date of birth and computes the exact elapsed time in years, months, weeks, days, hours, and minutes, counting calendar-correctly rather than by dividing total days. You can also set a target date to compute age as it will be, or was, on a specific day.
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Enter your date of birth using the date picker.
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The exact age in years, months, and days is calculated instantly based on today's date.
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Optionally set a custom target date to calculate age at a specific point in time.
Quickly calculate someone's exact age for forms, documents, or eligibility checks.
Find out how many days old you are for a fun milestone or birthday post.
Calculate age in months or weeks for infant development tracking.
Age from birthdate
Date of birth: 1990-06-1535 years, 9 months, 23 daysAge at a specific date
Born: 2000-01-01 | Target: 2024-01-01Exactly 24 years oldThe result is one day off
Cause: Time zones. The calculation uses your browser's local zone, so a birth date entered as a plain date is interpreted locally while a date recorded in UTC elsewhere may fall on the previous or following day.
Fix: Check that the date shown back to you matches the date on the document you are working from. For legal purposes, use the date as written on the birth certificate rather than a timestamp converted between zones.
Months and days do not match another calculator
Cause: There is no single convention for expressing a remainder in months. Counting from the birth date forward and counting backward from today give different day remainders when the two months have different lengths.
Fix: Expect small differences in the months-and-days breakdown between tools. The total elapsed days is unambiguous, so use that figure where an exact comparison is needed.
A 29 February birth date behaves oddly in non-leap years
Cause: The date does not exist in three years out of four, so any calculator must choose a substitute, and different systems choose differently.
Fix: Be aware that legal and administrative systems vary — some treat 28 February as the birthday, others 1 March. Where it matters, check the rule that applies in the relevant jurisdiction rather than assuming.
These answers explain common age calculator tasks, expected input formats, and edge cases so both visitors and search engines can understand what this tool does.
How is the age calculated?
Age is calculated from the entered date of birth to today's date using your local timezone. Years, months, and remaining days are computed separately for accuracy.
Does this tool account for leap years?
Yes. The day count is based on the actual difference in calendar days, so leap years are automatically accounted for.
Can I calculate the age of someone born today?
Yes — entering today's date will return zero for all fields, confirming the tool handles same-day entries correctly.
Can I calculate a date difference other than age?
Yes. Change the target date from today to any past or future date to calculate the exact difference between two dates in years, months, and days — useful for contract durations, project timelines, or anniversary countdowns.
How do I find out what day of the week I was born?
Enter your birth date and the tool displays the day of the week that date fell on alongside your exact age in years, months, and days.