Sometimes you know a person's age for a given date, and want to know what the person's age was or will be on another.

There are 2 approaches:

(1) simple

(2) accurate



(1) If a person is X years old in a given year, then year of birth is (given year) - X.

(2) For a second date, then the age would be (second date) - (year of birth).


If the birthdate is known, then the age can be determined more accurately. In Excel this can be determined by subtracting the various dates.

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