Amortization - Casio FX-CG20 AU User Manual

5. Amortization

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.
u Formula
1 payment 1 payment
a
: interest portion of installment PM1 (
b
: principal portion of installment PM1 (
c
: balance of principal after installment PM2 (
1 payment 1 payment
: total principal from installment PM1 to payment of installment PM2 ( Σ
d
: total interest from installment PM1 to payment of installment PM2 ( Σ
e
a b
* + = one repayment (
a : INT a : INT
b : PRN b : PRN
c : BAL c : BAL
d : d :
e : e :
1 1 ............ ............
Number of Payments Number of Payments
INT
1 1 ............. .............
Number of Payments Number of Payments
PMT
)
= I BAL = I BAL
PM1 PM1 PM1–1 PM1–1
= PMT + BAL = PMT + BAL
PM1 PM1
= BAL = BAL + PRN + PRN
PM2 PM2 PM2–1 PM2–1
Σ Σ
PM2 PM2
PRN = PRN PRN = PRN + PRN + PRN
PM1 PM1
PM1 PM1
Σ Σ
PM2 PM2
INT = INT INT = INT + INT + INT
PM1 PM1
PM1 PM1
a a
b b
PM1 PM1 ................... ................... PM2 PM2
)
PRN
)
BAL
)
e e
d d
PM2 PM2
PM1 PM1 ................ ................
× i I × (PMT sign) × i I × (PMT sign)
× i × i
PM1–1 PM1–1
PM2 PM2
+ ... + PRN + ... + PRN
PM1+1 PM1+1
+ ... + INT + ... + INT
PM1+1 PM1+1 PM2 PM2
7-9
c c
.......... .......... Last Last
............. .............
Last Last
PRN
)
INT
)
PM2 PM2