Sometimes you need to know accurate completed years based on a start date and today’s date. Here is a simple formula to calculate that.
The solution uses an unusual Excel function called DATEDIF which stands for date difference.
The image below has a list of start dates in column A. Column B has a formula that returns the completed years.
The formula in cell B2 is.
=DATEDIF(A2,TODAY(),"y")It has been copied down.
The TODAY() function returns today’s date.
In the DATEDIF function the first argument is the start date. The second argument is the end date.
The “y” in the third argument of DATEDIF specifies completed years between the two dates.
In the example dates on or before 24 February will be treated as a full year based on 2026. Whereas dates after 24 February will use 2025 as the year for calculation.
The DATEDIF function is unusual because Excel doesn’t assist you when creating it with the built-in Intellisense feature. You have to know how to use it.