Calculating number of Months between two dates by Year

Hello,

Need help with calculating the number of months between two dates, but by year. I keep running into multiple variables when checking the formula by changing the two dates. The attached formula is what i had been working with and building on, probably need a lot more in it. I want the start date to count as 1 month as well, that is why the EOMONTH formula is their. Also was thinking I would have to make a unique formula for each specific year, that is why the first and last day of the year are their.

Thanks for any assistance you can provide.

Maybe put in D4 and copied cross :

=((DAY((DATE(YEAR($B4),1+MONTH($B4),1)-1))-(DAY($B4)))/(DAY((DATE(YEAR($B4),1+MONTH($B4),1)-1))))+(DATEDIF($B4,DATE(D$3,12,1),"m")-1)+((DAY(DATE(D$3,12,1)))/(DAY(DATE(YEAR(DATE(D$3,12,1)),1+MONTH(DATE(D$3,12,1)),1)+1)))+1

Thanks for the reply. That formula seems to be only calculating between the start date and the end of the year. Was looking for the number of months between a start and finish date.
I attached more of what I was looking for.

Thanks

Try

in D4

=IF(YEAR($B$4)>D$3,0,IF(YEAR($B$4)=D$3,DATEDIF($B$4,EOMONTH($B$4,13-MONTH($B$4)),"m"),IF(D$3=YEAR($C$4),MONTH($C$4),IF(D$3>YEAR($C$4),0,12))))

Awesome. That works great for a start and finish date spanning across multiple years, but what about a start and finish date within the same year?
Is there something to add or change in the first DATEDIF formula?

Thanks

Try

=IF(OR(YEAR($B$4)>D$3,D$3>YEAR($C$4)),0,IF(YEAR($B$4)=YEAR($C$4),MONTH($C$4)-MONTH($B$4)+1,IF(YEAR($B$4)=D$3,DATEDIF($B$4,EOMONTH($B$4,13-MONTH($B$4)),"m"),IF(D$3=YEAR($C$4),MONTH($C$4),12))))

that seems to do it. thank you very much!!