Hello,

Can anyone tell me the calculation I need to do in order to work out roughly how much I am paying off of my mortgage per year? Is it just = total / years + % ?

You should get a statement each year with that information on it.

The calculation is complicated by the different ways that lenders apply the interest and also you are likely to be paying more capital and less interest towards the end of the mortgage term.

The exact calculation for a montly repayment of any loan with an interest of X% APR

First we calculate the monthly interest as the APR stand for Annual (yearly)
-ⁿ√ (1+ i )
example: for a 8%APR, the interest per month is:

-12↑√ (1+0.08) = 1.00643403 or 0.643403% per month

where n is number of repayment periods (12 months per year) and i stand for interest
We are now ready to calculate any repayment loan or mortgage over a certain period of time

i / (1 – ((1 + i )power of -n))

example: the monthly payment for a repayment mortgage of £450,000 over 25 years at 8% APR will be : (n=300 - 25years multiple by 12months)

0.00643403 / (1 – ((1+0.00643403)power of-300)) = 0.00753415 X 450,000 = £3390.36

And an interest only mortgage will be:
0.00643403 X £450,000 = £2895.31

It is a rather long process hence the bank clercks have a ready-made printed table at hand.
Hope it does answer your question!!!