Mortgage Calculator Instructions
- Sliders - move
the sliders to set the values of your principal, interest rate, loan
length, and mortgage start date.
- Data display -
use the buttons to choose how you want the output to be displayed:
- Summary - just
shows a summary of the current values.
- Amortization
Graph - this shows how the total payment made each year is broken
down. Note how the curves show increased principal and decreased
interest being paid as time goes by. Also note that extra payments
"push" up the principal curve, i.e. the annual principal amount
shown is increased by the value of the extra payment.
- Repayment Chart
- the percentage breakdown of the total payments made over the entire
mortgage (or indeed, the breakdown of the average monthly payment).
- Balance Graph
- this shows the balance outstanding over the term of the mortgage.
It is useful when extra payments are made to visually see how much
sooner the mortgage is paid off, and how quickly the balance drops.
- Annual Amortization
Table - how much interest and principal you pay each year.
- Monthly Amortization Table - how much interest and principal you pay each year, broken down month by month.
- Summary - just
shows a summary of the current values.
- Input Box
- Initial Loan
Data - if you don't like using the sliders, you can enter data directly
in this section. Values for the Tax and Insurance fields are simply
divided by 12 and added to the monthly payment amount. The inflation
figure allows estimates in real terms (i.e. in "today's money")
to be calculated. The total interest paid over the entire mortgage
is shown on the right hand side along with the total interest paid
as a percentage of all payments made (see the Repayment Chart for
a graphical view). Finally, the total interest paid in real terms
is displayed - this figure is an attempt at calculating how much
the total interest paid is worth in real terms.
- Prepayment Data - this section gives you the opportunity to estimate how you can shorten the term of your mortgage by making either a single one-off payment or continuous extra monthly or annual payments. On the right-hand side, the Savings field shows you how much money you will save, while the Real Savings field once again uses the inflation rate to give a rough estimate of what these savings are in real terms given that the interest savings are spread over a number of years. The dates shown reflect what happens to the mortgage term when the extra payments have been factored in.
- Initial Loan
Data - if you don't like using the sliders, you can enter data directly
in this section. Values for the Tax and Insurance fields are simply
divided by 12 and added to the monthly payment amount. The inflation
figure allows estimates in real terms (i.e. in "today's money")
to be calculated. The total interest paid over the entire mortgage
is shown on the right hand side along with the total interest paid
as a percentage of all payments made (see the Repayment Chart for
a graphical view). Finally, the total interest paid in real terms
is displayed - this figure is an attempt at calculating how much
the total interest paid is worth in real terms.
Important: When entering values into the "Input Box", make sure to press "Return" after you enter the last value. Using the TAB key will work on some browsers, and clicking the mouse over the next box is fine too, just make sure the last value you enter has been recognised by the calculator, and is being taken into account when calculations are made. If you find that nothing happens when you enter data in the prepayment fields, make sure that you are only entering whole numbers i.e. for an extra payment of €100.00, enter just 100 - no decimal points.