12-14-2019, 02:46 PM

Blog Link: http://edspi31415.blogspot.com/2019/12/h...-loan.html

Introduction

The program AMORT calculates:

* The monthly payment of a loan.

* An amortization table where the year's interest and principal is calculated.

* The amount of the final payment based on the balance.

Assumptions:

* Payments are made at the end of the month.

* The payment and the amount of interest calculated at each month are rounded to the nearest two decimal places. Not every one in finance follows this practice, so you mileage may very.

HP 71B Program: AMORT

Notes:

* There is no rounding command in the HP 71B's programming language. Lines 140 and 220 has a formula for rounding results to two decimal places:

IP(100*n+.5)/100

* STD is floating point display mode (standard)

* CHR$(28) prints the capital Sigma character, "Σ"

Examples

Example 1:

Loan: $35,000.00

Rate: 5.8%

Term: 5 years

Payment: $673.40

Year 1: Interest: $1,866.54, Principal: $6,214.26, Balance: $28,785.74

Year 2: Interest: $1,496.37, Principal: $6,584.43, Balance: $22,201.31

Year 3: Interest: $1,104.14, Principal: $6,976.66, Balance: $15,224.65

Year 4: Interest: $688.59, Principal: $7,392.21, Balance: $7,832.44

Year 5: Interest: $248.25, Principal: $7,832.55, Balance: -$0.11

Final Payment: $673.29

Example 2:

Loan: $76,000.00

Rate: 4%

Term: 6 years

Payment: $1,189.03

Year 1: Interest: $2,831.83, Principal: $11,436.53, Balance: $64,563.47

Year 2: Interest: $2,365.89, Principal: $11,902.47, Balance: $52,661.00

Year 3: Interest: $1,880.98, Principal: $12,387.38, Balance: $40,273.62

Year 4: Interest: $1,376.30, Principal: $12,892.06, Balance: $27,381.56

Year 5: Interest: $851.04, Principal: $13,417.32, Balance: $13,964.24

Year 6: Interest: $304.41, Principal: $13,963.95, Balance: $0.29

Final Payment: $1,189.32

Introduction

The program AMORT calculates:

* The monthly payment of a loan.

* An amortization table where the year's interest and principal is calculated.

* The amount of the final payment based on the balance.

Assumptions:

* Payments are made at the end of the month.

* The payment and the amount of interest calculated at each month are rounded to the nearest two decimal places. Not every one in finance follows this practice, so you mileage may very.

HP 71B Program: AMORT

Code:

100 FIX 2

105 INPUT "LOAN $";L

110 INPUT "RATE? ";I

115 I=I/1200

120 INPUT "TERM? ";T

125 N=12*T

130 U=(1-(1+I)^(-N))/I

135 P=L/U

140 P=IP(100*P+.5)/100

145 DISP "PAYMENT= $";P

150 PAUSE

155 B=L

200 FOR Y=1 TO T

205 S=0

210 C=0

215 FOR K=1 TO 12

220 E=IP(100*B*I+.5)/100

225 S=S+E

230 A=P-E

235 C=C+A

240 B=B-A

245 NEXT K

255 DISP "YEAR ";Y @ PAUSE

265 DISP CHR$(28);"INT= $";S @ PAUSE

275 DISP CHR$(28);"PRN= $";C @ PAUSE

285 DISP "BALANCE= $";B @ PAUSE

295 NEXT Y

310 W=P+B

315 DISP "LAST PMT= $";W @PAUSE

320 STD

Notes:

* There is no rounding command in the HP 71B's programming language. Lines 140 and 220 has a formula for rounding results to two decimal places:

IP(100*n+.5)/100

* STD is floating point display mode (standard)

* CHR$(28) prints the capital Sigma character, "Σ"

Examples

Example 1:

Loan: $35,000.00

Rate: 5.8%

Term: 5 years

Payment: $673.40

Year 1: Interest: $1,866.54, Principal: $6,214.26, Balance: $28,785.74

Year 2: Interest: $1,496.37, Principal: $6,584.43, Balance: $22,201.31

Year 3: Interest: $1,104.14, Principal: $6,976.66, Balance: $15,224.65

Year 4: Interest: $688.59, Principal: $7,392.21, Balance: $7,832.44

Year 5: Interest: $248.25, Principal: $7,832.55, Balance: -$0.11

Final Payment: $673.29

Example 2:

Loan: $76,000.00

Rate: 4%

Term: 6 years

Payment: $1,189.03

Year 1: Interest: $2,831.83, Principal: $11,436.53, Balance: $64,563.47

Year 2: Interest: $2,365.89, Principal: $11,902.47, Balance: $52,661.00

Year 3: Interest: $1,880.98, Principal: $12,387.38, Balance: $40,273.62

Year 4: Interest: $1,376.30, Principal: $12,892.06, Balance: $27,381.56

Year 5: Interest: $851.04, Principal: $13,417.32, Balance: $13,964.24

Year 6: Interest: $304.41, Principal: $13,963.95, Balance: $0.29

Final Payment: $1,189.32