"Bob Phillips" <bob.phillips@notheretiscali.co.uk> wrote in message
news:eEOR8VopFHA.1148@TK2MSFTNGP12.phx.gbl...
> You don't need the sum, and you don't need to multiply by -1, and assuming
> that the interest is calculated annually, then
>
> =-(B3*B4)/12
>
> --
>
> HTH
>
> RP
> (remove nothere from the email address if mailing direct)
>
>
> "Ron" <ron@flymail.fm> wrote in message
> news:uJfz%23RopFHA.320@TK2MSFTNGP09.phx.gbl...
>> Hi, is this the correct formula to calculate mortgage interest on an
>> interest only mortgage?
>> =SUM((B3*B4)/12)*-1 where B3 is the mortgage and B4 is the interest rate.
>> Thanks Ron
>>

Hi thanks for the quick reply however I have just had a notice from my
mortgage company, as the interest rate is decreasing and their calculations
for a mortgage of £45397.72 and an interest rate of 5.6%, gives a monthly
payment of £210.91, whereas my formula gives £211.83. They must use a
different formula.

As there is a shortfall in my endowment I was trying to find out the
difference in paying money into my mortgage account as against using an ISA
to make up the shortfall.



Ron