For me exact age means the exact number of years, the exact number of months and the exact number of days of your life in this planet. Your knowledge in Mathematics will be applied here to compute your exact age. It maybe by applying addition, subtraction, multiplication and division. Before computing your exact age, first you have to familiarize the months of year and days of months. There are twelve months in a year such as (1) January 31 days, (2) February 28 days plus 1, if it is leap year, (3) March 31 days, (4) April 30 days, (5) May - 31, (6) June 30 days, (7) July 31, (8) August 31 days, (9) September 30 days, (10) October 31 days, (11) November 30 days and (12) December - 31 days. Assuming you want to know your exact age today. Your birth date recorded on your birth certificate is December 23, 1980. Today is December 23, 2010. Your exact age is 30year old today. How did you arrive that answer? Looking at those dates, you immediately subtracted (2010 1980) = 30. This is right because you were born with the same month and day. The proper computation for your exact age based from those dates and by applying subtraction method will be: Present date minus your Birthday dateas shown below starting subtracting the day then month then year. 2010 12 23 - the present date, (year, month, day) December 23, 2010 1980 12 23- your birth date, (year, month, day) December 23, 1980 0030 0 - 0 - your exact age, 30year old What if you were born on December 29, 1980? How old are you today? To get your exact age here, you will apply the same formula: Present dateminus Birth date plus Borrowing the Year, the Month and Days and applyAddition and Subtractionmethods. 2010 12 23 - the present date, (year, month, day) December 23, 2010 1980 12 29- your birth date, (year, month, day) December 29, 1980 x x x your exact age today Step One: You cannot subtract 29 from 23 as 29 is higher than 23. What you will do is to borrow days from month and add them to 23. In this calculation the number of days of every month is ignored. It is normally believed that a month is equals to 30 days. So 23 become 53 days (23 30). Step Two: Because you borrowed one month which is equals to 30 days from the month of present date, the 12 became 11. Now you cannot subtract 12 from 11 as 12 is higher than 11. What you will do is to borrow months from year and add them to 11. One year is equals to 12 months. So 11 become 23 months (11 12). Step Three: After borrowing 1 year which is equals to 12 months, the year 2010 become 2009. Now to get your exact age, consider the changes of the present date December 23, 2010 which is 2010-12-23 became 2009 the year, 23 the number of months and 53 the number of days or 2009-23-53. While your birthdate remains the same as shown below. 2009 23 53 - the present date, (year, month, day) December 23, 2010 has changed. 1980 12 29- your birth date, (year, month, day) December 29, 1980 remains the same. 29 - 11 - 24 - So today you are 29 year old, 11 months and 24 days. Happy Birthday.