NeoCal User Guide
Amortization
This application uses the
, and
registers to calculate the
amount of interest and principal for a range of payments. The
remaining balance is also calculated.
- Pressing
while entering a number
will amortize for the range of payments starting with y and
ending with x (inclusive).
- Pressing
by itself will calculate the
interest, principal, and balance for the range of payments currently
entered (which defaults to the first payment, or range 1-1).
- Pressing
will amortize the next range of
payments. For instance, if the current range of payments is 1-12
(the first year), then the next range is 13-24 (the second year).
- Pressing
after pressing
or
will display the
principal. Pressing
a second time will
display the balance. As a convenience, pressing
a third time will calculate the amortization for
the next range of payments.
- In RPN mode, press
to display the
principal. Pressing
a second time will
display the balance. Press
to calculate the
amortization for the next range of payments.
- Pressing
will store
y and x as the starting and ending payments.
(Pressing
a second time will perform the calculation.)
- Pressing
recalls the
starting and ending payments into the y and x
registers, respectively.
-
switches between begin and end
modes and is used to specify whether compounding occurs at the
beginning or the end of the period. When begin mode is
selected, the BEGIN indicator is displayed, otherwise
end mode is in effect.
The amortization calculation is sensitive to rounding errors and
may not match your financial institution's calculations exactly
(different institutions use different rounding rules). NeoCal will
round the intermediate results based on the display setting for the
number of digits to the right of the decimal place, therefore, this
setting affects the results.
Let's look at a mortgage example, $200,000 for 30 years at an
annual nominal rate of 7 percent with payments and compounding
occurring monthly.
- Set the display to show two decimal places in the Preferences dialog.
- If the calculator is in begin mode, press
to set end mode.
- Press
to clear the financial registers.
- Press
for monthly payments.
- Press
to store the loan duration in the
register.
- Press
to store the
interest rate.
- Press
to store the loan amount in the
present value register.
- Press
to calculate the monthly payment amount (-1330.60).
- Press
to amortize the first payment and
display the interest amount (-1,166.67).
- Press
(in RPN mode, press
) to display the principal for the first payment (-163.93).
- Press
(in RPN mode, press
) to display the balance after the first payment (199,836.07).
- Press
(in RPN mode, press
) to amortize the second payment and display the
interest amount (-1,165.71). This process can be repeated through
the term of the loan.
To calculate the amount of interest paid during the first year of
the loan,
- Press
to amortize
the first twelve payments and display the interest amount (-13,935.65).
- Press
to amortize the second year's
payments and display the interest amount (-13,788.78).
At any time, you can press
to recall the starting and ending payments for the
range being amortized. (Use the
button to
display the starting payment.)