The Excel YEARFRAC function returns a decimal value that represents fractional years between two dates. You can use YEARFRAC to do things like calculate age with a birthdate.

**Syntax**: =YEARFRAC (start_date, end_date, [basis])

The YEARFRAC function syntax has the following arguments:

**Start_date**(required argument) – This is the start of the period. The function includes the start date in calculations.**End_date**(required argument) – This is the end of the period. The function also includes the end date in calculations.**[basis]**(optional argument) – Specifies the type of day count basis to be used.**Basis****Day count basis**0 or omitted US (NASD) 30/360 1 Actual/actual 2 Actual/360 3 Actual/365 4 European 30/360

**Example**: Let’s look at some Excel YEARFRAC function examples and explore how to use the YEARFRAC function as a worksheet function in Microsoft Excel:

**Syntax**: =YEARFRAC(A2,B2,1)

**Result**:

Based on the Excel spreadsheet above, the following YEARFRAC examples would return:

**Syntax**: =YEARFRAC(A3,B3)**Result**: 0.75

**Syntax**: =YEARFRAC(A4,B4)**Result**: 1

**Syntax**: =YEARFRAC(A5,B5,1)**Result**: 0.330601093

**Syntax**: =YEARFRAC(A6,B6,3)**Result**: 0.583561644

**Syntax**: =YEARFRAC(A7,B7)**Result**: 0.75

**Syntax**: =YEARFRAC(A8,B8)**Result**: 0.25

**Syntax**: =YEARFRAC(A9,B9,3)**Result**: 0.668493151

**Syntax**: =YEARFRAC(A10,B10,3)**Result**: 0.832876712

**Syntax**: =YEARFRAC(A11,B11)**Result**: 0.416666667

**Syntax**: =YEARFRAC(A12,B12)**Result**: 0.416666667

**Note**:

- If the dates you are using are not working, input them with the DATE() function.
- #NUM! error – Occurs when the given basis argument is less than 0 or greater than 4.
- #VALUE! error – Occurs when:
- The start_date or end_date arguments are not valid dates.
- The given [basis] argument is non-numeric.