From: John Boyle 
Newsgroups: uk.finance
Subject: Re: Mortgage spreadsheet
Date: Mon, 12 Feb 2007 19:58:57 +0000

In message <45d08c56$0$8714$ed2619ec@ptn-nntp-reader02.plus.net>, David 
Day  writes
>Hi,
>
>Ive read a fair bit on here about apr's etc on savings. Ive done the same
>formula for my mortgage but taking away payments. The figures I get, dont
>match the figures given by my mortgage company. Could someone please help me
>a little.
>
>I have a fixed mortgage for 3 years at 5.99% then it goes up to 6.59%
>
>=(1+5.99%)^(E4/365)*F3-(C4+D4)    as given by GSV earlier
>
>where I have:
>E4 is number of days in month
>F3 is initial loan amount
>C4 is monthly repayment
>D4 is an overpayment amount (im hoping to make overpayments soon, hence this
>spreadsheet)
>
>this formula is in box F4. and is copied down for the full 360 months.
>
>I get a difference of 11K at the end of the mortgage period. Can anyone
>throw any light my mistake(s).

The interest doesnt compound daily as GSV's formula implies. Most accrue 
daily and compound annually but there are a number of variations. Have a 
look at your last mortgage statement and see if they apply interest 
monthly or annually.
-- 
John Boyle