The YEARFRAC function in Excel returns a decimal value that represents fractional years between two specified dates.


=YEARFRAC(start_date, end_date, [basis]) 


  • start_date – The start date.
  • end_date – The end date.
  • basis – [optional] The type of day count basis to use (see image below).

YEARFRAC Function Example

As mentioned above, Excel calculates a decimal number that represents the fraction of a year between two dates. Excel also uses whole days when calculating the fractional data. Let’s look at the example below. Pay attention to how the optional argument changes the result.