Casio fx-9750G PLUS - Manual (Page 369)

341
Investment Appraisal
19 - 4
19-5 Amortization of a Loan
This calculator can be used to calculate the principal and interest portion of a
monthly installment, the remaining principal, and amount of principal and interest
repaid up to any point.
b
a
d
e
c
1 2 m n
a : Interest portion of installment PM1 ( INT )
b : Principal portion of installment PM1 ( PRN )
c : Balance of principal after installment PM2 ( BAL )
d : Total principal from installment PM1 to payment of installment PM2 ( Σ PRN )
e : Total interest from installment PM1 to payment of installment PM2 ( Σ INT )
* a + b = one repayment ( PMT )
a : INT
PM1
= I BAL
PM1–1
× i I × (PMT sign)
b : PRN
PM1
= PMT + BAL
PM1–1
× i
c : BAL
PM2
= BAL
PM2–1
+ PRN
PM2
d :
Σ
PRN = PRN
PM1
+ PRN
PM1+1
+ … + PRN
PM2
e :
Σ
INT = INT
PM1
+ INT
PM1+1
+ … + INT
PM2
PM2
PM1
PM2
PM1
BAL
0
= PV ( INT
1
= 0 and PRN
1
= PMT at beginning of installment term)
u u u u 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 %') for installment loans where the number of installments per year
is different from the number of compound interest calculation periods.
I%' =
I%
(1+ ) –1
[C / Y ]
[P / Y ]
100 × [C / Y ]
{ }
×100
(Number of payments)
Amount of single payment