User's Manual

20070201
• A deposit is indicated by a plus sign (+), while a withdrawal is indicated by a minus sign (–).
u Converting between the nominal interest rate and effective interest rate
The nominal interest rate ( I % value input by user) is converted to an effective interest
rate ( I % ' ) when the number of installments per year ( P/Y ) is different from the number of
compound interest calculation periods ( C/Y ). This conversion is required for installment
savings accounts, loan repayments, etc.
P/Y : installment
periods per year
C/Y : compounding
periods per year
When calculating
n , PV , PMT , FV
The following calculation is performed after conversion from the nominal interest rate to the
effective interest rate, and the result is used for all subsequent calculations.
When calculating I %
After
I % is obtained, the following calculation is performed to convert to I % ' .
P/Y : installment
periods per year
C/Y : compounding
periods per year
The value of I % ' is returned as the result of the I % calculation.
FV = – (PMT × n + PV )FV = – (PMT × n + PV )
n
PMT = –
PV + FV
n
PMT = –
PV + FV
PMT
n = –
PV + FV
PMT
n = –
PV + FV
I%' =
I%
(1+ ) –1
[C / Y ]
[P / Y ]
100 × [C / Y ]
{ }
× 100
I%' =
I%
(1+ ) –1
[C / Y ]
[P / Y ]
100 × [C / Y ]
{ }
× 100
i = I%'÷100 i = I%'÷100
I%' =
I%
(1+ ) –1
[C / Y ]
[P / Y ]
100
{ }
× [C / Y ] × 100
I%' =
I%
(1+ ) –1
[C / Y ]
[P / Y ]
100
{ }
× [C / Y ] × 100
7-3-2
Compound Interest