Practical, plain-language guides about age calculations, birthdays, dates, milestones, and eligibility rules.
If the date of birth is in cell A2, the simplest way to calculate the person’s current age in completed years is: =DATEDIF(A2,TODAY(),"Y") In this formula, A2 contains…
Calculating age in software looks simple until the date of birth falls near a birthday, leap day, month end, or timezone boundary. For completed age in years, start…
Age calculations can be wrong even when the arithmetic looks simple. The most common causes are using the wrong reference date, subtracting only the birth year, misreading the…
To calculate how many days are left until your birthday, first find the next occurrence of your birthday month and day. If your birthday is still ahead this…
If you were born on February 29, you still get older every year. Your age is not divided by four, and it does not increase only when another…
To calculate age from a date of birth manually, you need two dates: the date of birth and the reference date, which is the date you want to…
If a date of birth is stored in cell A2, the simplest Excel formula for calculating the person’s current age in completed years is: =DATEDIF(A2,TODAY(),"Y") The formula compares…
To calculate age at death, use the person’s date of birth as the starting date and their date of death as the ending date. For completed age in…
To calculate your age on a specific past or future date, use your date of birth as the starting date and the date you want to check as…
