Age Calculator: Calculate Age in Years, Months, Days & Next 3 Birthdays

How Does This Calculator Work?

Most of us say that “I am 25”, or “I am 30”, meaning that we round our ages to the nearest year. However, time does not break down by years. You need to be able to break down your age into many different formats as well.

This is a multi-dimensional calculator, and can generate your actual age in each of the following formats:

• Standard Break Down: Years, months and days.
• Complete Count Alive: In months, weeks, days, hours, minutes and seconds
• Future Birthday: Displays the dates that you will celebrate your birthday three years from now.
• Real-Time Updates: Updates your results instantly as you change the dates.

No more guesswork when determining your age; The Age Calculator will do the hard work for you. It automatically considers all the issues with calendar calculations, including leap years, differences in month lengths, and all other calendar-related issues.

The interface is very user-friendly. You will enter the two dates, and will receive instant results and the option of copying or saving your results. There is no need to register, and there is no way for your data to be saved.

Real-life Applications for This Calculator

• When applying for a visa or immigration, officials need your age calculated accurately. Some countries require that you show your age in years, months, and days when you submit a visa application. A lot of visa programs are subject to strict limits based on when you reach an age based on the number of days you’ve lived. If you are 9,125 days old, you may qualify for one program. If you are only 9,124 days old, you may not qualify. One day can determine your eligibility for a visa/immigration program.
• Individuals submitting applications for employment through a job seeker background check will frequently need to provide their exact date of birth. Many of these requests are made by the federal government for employment with government agencies or government contractors and/or for employment with the military or for age-restricted positions.
• Child enrollment in school must be based on specific cut-off ages for the school’s school year. Your child may be required to be exactly 5 years and 0 days old by September 1st to qualify for kindergarten. Gifted education program enrollment can utilize month cut-off criteria to determine eligibility for enrollment.
• Insurance benefit cost is calculated based on the precise age of the insured. Creation of life insurance policies, health insurance policies, and retirement benefit programs all calculate life insurance premiums based on the insured’s date of birth. An age difference of even a few months can result in a difference in the cost of an insurance premium or in the types of coverage available.
• Accurate age determination is critical to determining proper dosing, treatment, and developmental milestones in healthcare and medical tracking. Pediatricians approximate baby growth in weeks/months of life. Age-based screenings for disease occur at specific age intervals (e.g., colonoscopy at 45 years old).
• Accuracy in verifying the legal age of individuals is also critical in verifying signatures on legal contracts, obtaining legal permissions (e.g., voting/ driving), and applying for licenses. Certain jurisdictions and/or country laws require an individual being of a certain number of days old to be eligible to vote, be able to drive and/or sign legal documents. Adoption agencies, as well as foster care and family courts, use exact age as their basis for placement decisions.
• Many sports and athletic events create age categories by which participants are grouped according to their precise ages. Age grouping is how youth leagues, Olympic qualifiers, amateur competitions, as well as others, establish their divisions. Individuals who are 17 years 364 days old are placed in a different division than those who are 18 years 0 days old.
• Exact age is required for most financial planning and retirement calculations. Social Security benefits, pension plans, and retirement accounts are all dependent upon exact age to determine if an individual is eligible to receive benefits at the time they reach specific ages.
• Milestones and celebrations within relationships can be made even more special by knowing the specific ages associated with those relationships.

Using this Calculator is Simple!

To start, just enter your birth date into the first field either by clicking the calendar icon or by typing the date directly in the format of MM-DD-YYYY (e.g., 12-15-2026).

Below the birth date field, you’ll see the current date filled in automatically for you. This date will get automatically filled out for you, but you can change it if you are trying to find out how old you will be on a specific date in the future or how long ago you were born.

Once you have selected both dates, you can see your exact age in the results section on the top line, which gives your age as “X years, Y months and Z days”.

Next, scroll to the bottom of the results and you will see the breakdown of your time as an adult (from date of birth to the current date) shown as follows:

• Total number of months you’ve been alive (includes partial months)
• Total number of weeks (complete week count from your date of birth until today)
• Total number of days (number of days from your date of birth until today)
• Total number of hours (total number of days multiplied by 24)
• Total number of minutes (total number of days multiplied by 1,440)
• Total number of seconds (total number of days multiplied by 86,400)

At the bottom of your results, there are three upcoming birthdays with the exact date and day of the week so that you can plan your future birthdays and see when your next weekend birthday will occur! 

You can copy your results by clicking the “Copy” button. This will copy your age summary and total number of days as plain text for you to paste into forms, emails, and other documents. 

You can also save these results as an image file (screenshot) by clicking the “Save” button. You can use this image (screenshot) as a record, application, or to post on social media!

If you want to go back to default dates, you can reset the calculator using the “Reset” button. This will clear both inputs and recalculate your age based on today’s date. 

There is no need to click “Calculate” or submit anything; the calculator updates automatically whenever you enter a value in either date field. When either of the date fields contains a new value, you will immediately see the effects on your calculation results.

Mathematical Formula for Age Calculation

This calculator uses the following formula to calculate date differences:

Year calculation

$$\text{Years} = \text{Current Year} – \text{Birth Year}$$

Month Calculation

$$\text{Months} = \text{Current Month} – \text{Birth Month}$$

Days Calculation

$$\text{Days} = \text{Current Day} – \text{Birth Day}$$

Total Days Calculation:

$$\text{Total Days} = \frac{(\text{Current Date} – \text{Birth Date})}{\text{86,400,000 milliseconds}}$$

Accuracy Adjustments

If the day Is negative (the current day falls before the Birth date), the calculator makes the following adjustments:

• Deduct 1 from the month count.
• Determine the number of days in the last month.
• Add those days to the negative day value in order to obtain a positive number.

If the month is negative (the current month occurs prior to the Birth month) the calculator:

• Deducts 1 from the year Count.
• Adds 12 to the month count to make it positive.

This process helps produce accurate results when the dates do not add to a whole number.

Important Notes and Disclaimers

• The Gregorian Calendar is currently the world’s most popular and widely used calendar system today. Therefore, the default calculation of your age reflects the Gregorian Calendar. If you have documents that show your birthdate using a calendar type that differs from the Gregorian Calendar (i.e., Lunar Calendar, Solar Calendar, Traditional Calendar, etc.), your age as determined by those documents may differ from your age as determined by the Gregorian Calendar.
• The legal definition of age (adult, minor, senior) differs from jurisdiction to jurisdiction. Although your calculated age has been determined from your actual calendar date of birth, it is still advisable to verify your age against official sources that provide documentation of a minimum required age based on the applicable jurisdictional law.
• The method of calculating age is unique to each country. For example, in South Korea, the traditional method of counting someone’s age at birth counted them as 1 year old at birth and was then increased by 1 year every time they had a birthday. While South Korea has recently adapted an international approach for counting age, there are many countries – and possibly even some states/provinces – that have their own unique customs for counting people’s ages. This calculator uses the internationally accepted method for calculating a person’s age.
• Some applications may require the use of rounded ages. When completing a given form, verify if the age requested will be rounded down, rounded up, or calculated as of a specific date. For example, some insurance companies round ages based on the closest half-year and some schools base their cut-off date for entering 1st grade on September 1st regardless of the actual date of birth.
• This tool only processes your birth date while on your browser and does not save, transmit, or retain any data and if you close this page, all data relating to your birth date will disappear.
• Time zone impacts how your date of birth may differ. An example of this is being born just before midnight in one time zone and being born after midnight in a different time zone. You should refer to official documents for international applications that request your date of birth.
• Leap Year babies (February 29) are treated differently by this calculator. When you enter February 29 as your birthday, this calculator has this date validated. On years that are not leap years, this calculator will treat your birthday as being on March 1 when calculating your age.

This calculator can be used when you apply for a visa, confirm your qualifications for a program or as a reminder of the number of days you have been with somebody you love. Your Birthday age can be more than just an age. You now have your exact Birthday age, thanks to using this calculator!