Age Calculator

Age is calculated in various time units by this calculator. It offers options to determine age or time period in years and months and days, months and days, weeks and days, or simply in days.

In case if you needed to find out “How many weeks old am I?”, or even “How many days old am I?,” then the result is calculated as “total number of weeks” and “total number of days”. Age is also calculated in total hours, total minutes, and total seconds.

The new version of this age calculator also allows calculating date of birth from age on a particular date. This tool can also be used for calculating date of death from age at the time of death to find lifespan. If age is available only in years or in years and months, this calculator calculates the birth date range.

What is My Age?

With this chronological age calculator, you will be able to easily determine your age. Just enter your date of birth along with the current date to get your exact age. However, you can enter another ending date to know your age on that specific date. The remaining days until your birthday or event date are shown under every age calculation.

How Old is My Child?

New parents of a baby or an infant usually need to calculate in weeks or months to explain how old their child is to another person. This calculator will automatically give you weeks and months of age when calculating the age of anyone.

If you want to know the age in weeks of your baby, simply enter the date of birth of your child and hit the Calculate button. The “Find Age on” fields are automatically filled with the current date but you can also choose a future date.

Date of Birth Calculation

If you have information about someone’s age at a particular date, the tool will help you determine their date of birth. The calculator is useful in cases where genealogical sources indicate a certain individual’s age in respect to some census date, marriage certificate, or any other source.

Choose the “Date of Birth” option from the Calculate drop-down menu, enter the age (years, months, and/or days) and the date at which the individual had this age. Click Calculate, and you will receive the date of birth. In case you have only the age (in years) but no month and day, the tool will give you a range of dates.

Date of Birth Calculation

This calculator will give you a person’s date of death based on his/her date of birth and age of death. The tool will be helpful if you need to calculate the longevity of your ancestor in the case of genealogy studies or verify data based on a document with a person’s age of death.

Choose “Date of Death” from the Calculate drop-down menu, specify date of birth and age of death, and press the Calculate button. If you have the number of years only but not months and days of age, the calculator will show you a period when a person died.

Age Calculation Using This Calculator

The age calculation tool is one which applies programming language date-time functions for computing age. The user enters his inputs into the date and time functions, which then compute the difference between two dates. Otherwise, the inputs of age along with a reference date lead to date of birth or date of death computations.

Method of Calculating Age

Two methods exist for determining age or date differences manually. In one method, the following are added up to determine age in terms of the total number of days:

• Number of years, x, with 365 days = 365 * x plus,
• Number of leap years, y, with 366 days = 366 * y plus,
• Number of days in the remaining partial year

The output will be the number of years, plus the number of days remaining in the current year.

Second Method
You can align the dates similar to that of a subtraction problem. The date should be in the format of yyyy mm dd, with the more recent date on top, and the older date on the bottom. Below are the instructions on how to subtract two dates using this method.

• Set up the dates like you would set up long subtraction, listing the dates in year, month and day format from left to right.
• Start all the way on the right and subtract days. If necessary, borrow 1 from months. The number of days borrowed will be equal to the number of days in the month you are shifting to.
• Then move to the left and subtract months. If necessary, borrow 1 year and add 12 months to months.
• Move to the left again and subtract years.
• The age or date difference result will be in years, months, and days

Example for Calculating Age

Your goal is to find out how old someone will be on March 10, 2026, knowing that he or she was born on November 15, 2006.
Arrange the two dates in the manner that would normally be followed in subtracting one long number from another.

• Subtract days, 15 from 10. This would result in a negative number so you need to borrow months.
• Borrow 1 from the months column. When you borrow a month you are shifting back 1 month, from March to February. The number of days you are getting for that month is the number of days in that month, 28 in this case. Going from 3 (March), to 2 (February), move those days to the day column, adding them to the original 10 days there.
• 10 + 28 = 38
• Then subtract days.
• 38 – 15 = 23

How Many Days Until…?

To determine manually the number of days that will take place before some date or occasion occurs, leap years are considered where more days are added to make a year. Also, information on which months have 31 days, 30 days, and 28 days is required.

Number of days in a month

• January – 31 days
• February – 28 days in a regular year
• February – 29 days in a leap year
• March – 31 days
• April – 30 days
• May – 31 days
• June – 30 days
• July – 31 days
• August – 31 days
• September – 30 days
• October – 31 days
• November – 30 days
• December – 31 days

It is possible to count the days that are remaining until your special days such as your birthday, Thanksgiving, Independence Day, and beginning of your holiday season. As long as your date is not more than one year away, add up all the days that each of the full months has from the present moment to your desired date. Add the days of the current and the previous partial months to your total number of days.

To find out the number of days until your event date, you can use our Age Calculator. Enter today’s date into the box “Date of Birth”, and put your event date into the box “Find Age on”. Our tool will provide you with the required information.

Date Inputs

With the age calculator, you can enter the days using one digit only. There is no need to use the leading zero for days that are lower than 10. Please enter the year using four digits.

In this calculator, the starting date is considered day 0 and counting starts after one complete day. For instance, if you insert the date 03/15/2022 and 3/18/2022 in the calculator, the result will be 3 days old. The first day is on the 16th, the second day is on the 17th, while the third day is on the 18th.

How to Compute Your Age Using your Date of Birth on MS Excel

It is possible to use Excel for calculating age or time elapsed from a particular date or incident. If you wish to calculate the number of years elapsed from a certain date of birth or incident, then enter the month, date, and year in an Excel cell in the form of MM/DD/YYYY. You may calculate the age by using the formula =DATEDIF(A1, TODAY(), “Y”), where A1 is the cell that holds the date of birth or incident.

If you need the number of months and days since the date of birth, use this formula in another cell: =DATEDIF(A1, TODAY(), “YM”). This will give you the full months. Finally, in another cell, type =DATEDIF(A1,TODAY(),”MD”) to find the remaining days since the date of birth or event.

You can use the “CONCAT” function to string your results together like this: =CONCAT(A2, ” years, “, A3, ” months, “, A4, ” days “). Here, A2, A3 and A4 refer to your outputs years, months, and days respectively.