User Manual

Table Of Contents
7-9
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
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 )
c
a
1 payment
Number of Payments
1 PM1 PM2 Last............ ................... ..........
b
1 payment
Number of Payments
1 PM1
PM2
Last............. ................
.............
e
d
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