This is a well-known problem, you are by no means the first.

If the start date has 31 days, Apr/Jun/Sep/Nov all have issues if your start
date is the 31st.

Only Feb has issues if your start date is the 30th.

You can circumvent it by foirving DATEDIF to work on an earlier date



=IF(I$6<$G14,"",IF($F14<0,"N/A",IF(DATEDIF($G14-DAY($G14)+1,I$6-DAY(I$6)+1,"
m")/$B$3*$F14$F14,"",DATEDIF($G14-DAY($G14)+1,I$6-DAY(I$6)+1,"m")/$B$3*$F14
)))


--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Dave F" wrote in message
...
Here's the formula:


=IF(I$6<$G14,"",IF($F14<0,"N/A",IF(DATEDIF($G14,I$6,"m")/$B$3*$F14$F14,"",D
ATEDIF($G14,I$6,"m")/$B$3*$F14)))

I6 is 4/30/2006, G14 is 3/31/2006, F14 is $85,968, B3 is 48

I think it should resolve to 1/48*$85,968 = $1,791. But excel is
calculating it as $0.00.

Thoughts?

--
Brevity is the soul of wit.