What Is an Age Calculator?
An age calculator is a free online tool that works out your exact age — in years, months, weeks and days — based on your date of birth and any reference date you choose (defaulting to today). Instead of counting on your fingers or doing the math by hand, a date of birth calculator gives you an accurate answer instantly, including how many total days, weeks, months, hours and minutes you have been alive.
People use an online age calculator for many reasons: checking eligibility for school admissions, jobs, government forms and exams, planning birthdays, or simply out of curiosity about "how old am I" down to the exact day.
How to Calculate Age From Date of Birth
To calculate your age from your date of birth, subtract your birth year, month and day from the current year, month and day (or from any other reference date). If the day or month of the reference date is smaller than your birth day or month, you borrow a month or year, the same way you would when subtracting numbers with borrowing. Our exact age calculator performs this calculation automatically as soon as you press Calculate.
Age Calculator Formula
In simple terms, the age calculation formula is:
Age = Reference Date − Date of Birth, broken down into full years, remaining months and remaining days.
For the total-days view, the formula is simply the number of calendar days between your date of birth and the reference date, which this age calculator also converts into total weeks, total months, total hours and total minutes.
How Does This Calculator Work?
Enter Your Date of Birth
Select the month, day and year of your date of birth.
Choose a Reference Date
Optionally set "Age at the Date of" to any past or future date.
Click Calculate
Instantly see your exact age in years, months, weeks and days.
Age in Years, Months and Days
This age calculator shows your age in years, months and days at a glance, and also breaks it down further into the total number of months, weeks, days, hours and minutes since your date of birth — useful if you have ever wondered how many days old you are, how many months old you are, or how many weeks old a baby is.
Calculate Age on a Specific Date
Use the "Age at the Date of" field to calculate your age on a specific date, in the past or the future. This is useful for working out age eligibility for a school year, exam, visa application or retirement date, or for finding the age difference between two dates.
Age Calculator for Past and Future Dates
Because this online age calculator accepts any reference date, you can also use it as a simple date difference calculator: enter an earlier date of birth and a later or earlier reference date to see the age or duration between them in years, months and days.
Example of Age Calculation
If your date of birth is 15 August 2000 and you calculate your age as of 30 August 2026, this exact age calculator would show an age of 26 years, 0 months and 15 days, along with the total number of days, weeks and months you have lived.
Common Uses of an Age Calculator
An online age calculator by date of birth is useful in far more situations than simply satisfying curiosity about "how old am I today". Common uses include:
- School and college admissions — checking whether a child meets the minimum age requirement for a class or grade on a specific cut-off date.
- Job and exam eligibility — many government jobs, competitive exams and licenses set minimum and maximum age limits calculated as of a fixed date.
- Visa and travel documents — some visa categories require an applicant's exact age on the date of travel or application.
- Retirement and pension planning — working out age on a future retirement date.
- Birthday planning — finding out how many days are left until the next birthday.
- Pet and baby age tracking — parents and pet owners often want age in weeks or months rather than years.
Age Calculator vs Manual Calculation
Working out age by hand is easy to get wrong, especially around leap years and months with different numbers of days. A calculate-my-age tool like this one removes that risk: it always accounts for leap years correctly and gives the same accurate result every time, whether you need your age in years and months, or a full breakdown in weeks, days, hours and minutes.
Age Calculator for Different Needs
While this tool is built as a general date of birth calculator, the same age-calculation logic applies whether you are checking a chronological age for a form, working out a child's age for school records, or simply finding your age for a social media profile. For age calculations that are not based on the human calendar — such as a dog's age in "dog years" — you would need a species-specific converter rather than a standard age calculator, since those use different aging rates rather than calendar dates.
Frequently Asked Questions
Enter your date of birth in the calculator above and click Calculate. The age calculator instantly works out your exact age in years, months and days, along with your total age in weeks, days, hours and minutes.
Yes. Set the "Age at the Date of" field to any date to see what your age was, or will be, on that date.
Yes, this age calculator works for both past and future reference dates, so you can plan ahead and see your exact age on any future date.
The calculator uses calendar-accurate date math, including leap years, so your age in years, months and days is exact, not an estimate.
The calculator finds the difference between your date of birth and the reference date, broken down into full years, remaining months and remaining days.
Yes. Along with years, months and days, the result also shows your total age in months, weeks, days, hours and minutes.
After you calculate your age, the result section shows your next birthday date and a countdown of how many days are left until it.
Yes. Leap years and their extra day in February are handled automatically, including for people born on 29 February.
Yes, this free age calculator can be used online as many times as you like, without creating an account.
No. The calculation runs in your browser, so your date of birth is not stored or sent anywhere.
Age is simply the date difference between your date of birth and a reference date. You can use this same calculator as a general date difference calculator by entering any two dates.
Yes. Chronological age is simply the exact time elapsed since birth, which is exactly what this calculator computes in years, months and days.