HP 12C Programming III: Refinancing, Advance Payments in a Lease, NPV, NFV, NUS

HP 12C Programming III: Refinancing, Advance Payments in a Lease, NPV, NFV, NUS

HP 12C Programming Part I:  Modulus, GCD, PITI 

Link:  http://edspi31415.blogspot.com/2016/07/hp-12c-programming-part-i-modulus-gcd.html

HP 12C Programming Part II:  Weekday Number, Gross Up Calculation

Link:  http://edspi31415.blogspot.com/2016/07/hp-12c-programming-part-ii-weekday.html

HP 12C Refinancing:  When refinancing “resets” the clock.

Sometimes when a long term mortgage is refinanced, the original length of term is reset.  We will assume payments are made monthly.

Input: 

Store the following amounts in the registers:

Clear the TVM variables by pressing [ f ] [x<>y] (CLEAR FIN)

Original number of payments,  [ n ]

Annual rate, [ 12÷ ] [ I ]

Loan Amount, [ PV ]

Number of payments that have been made prior to refinance, [STO] [ 0 ]  (R0)

New annual rate, [ENTER], 12, [ ÷ ], [STO] [ 1 ]  (R1)

Run the program by pressing [R/S].  The original payment is calculated.  Press [R/S] again to get the balance.  Enter any additional monies (can be $0.00) received due to the refinance.  Finally, press [R/S] again, and the new payment is calculated.

Program:

STEP	CODE	KEY
01	45, 11	RCL n
02	44, 2	STO 2
03	14	PMT
04	14	PMT \\ calculate payment
05	31	R/S
06	45, 0	RCL 0
07	11	n
08	15	FV
09	31	R/S  \\ calculate balance, ask for amount of withdrawn
10	30	-
11	16	CHS
12	13	PV
13	0	0
14	15	FV
15	45, 1	RCL 1
16	12	i
17	45, 2	RCL 2
18	11	n
19	14	PMT
20	43, 33, 00	GTO 00

Example: 

A couple purchased a house for $185,000.  The mortgage lasts for 30 years (360 months) with a 4.8% interest rate (0.4% periodic rate).   180 payments have passed, and the couple is able to refinance the mortgage (but pay that amount in 30 years) at a rate of 3.84%.  $15,000 is also cashed out.

Input:

360 [ n ]

0.4 [ i ]

185000 [PV]

180 [STO] [ 0 ]

0.32 [STO] [ 1 ]

Results:

[R/S]    -970.63  (The original payment is $970.63)

[R/S]    -124,373.78   (Balance of $124,373.78)

Enter 15000, press [R/S] -652.60   (New payment is $652.60)

HP 12C:  Advance Payments in a Lease

The program calculates the payment where you pay number of payments in advance.

Formula:

PMT = (-PV – FV*(SPPV(I%/12:N))) ÷ (UPSV(I%/12:N-ADV)+ADV)

Where:

SPPV:  present value of $1, where FV is equal to 1

USPV:  present value of $1, where PMT is equal to 1

Input:

Number of payments, [ STO ] [ 0 ]

Number of payments made in advance, [ STO ] [ 1 ]

Periodic Rate, [STO] [ 2 ]

Price of the Lease, [STO] [ 3 ]

Salvage Value, [ STO ] [ 4 ]

Calculate lease payment by pressing [R/S].

STEP	CODE	KEY
01	42, 34	Clear FIN  ([ f ] [x<>y])
02	1	1
03	16	CHS
04	15	FV
05	45, 2	RCL 2
06	12	i
07	45, 0	RCL 0
08	11	n
09	13	PV
10	45, 4	RCL 4
11	20	*
12	16	CHS
13	45, 3	RCL 3
14	30	-
15	45, 11	RCL n
16	45, 1	RCL 1
17	30	-
18	11	n
19	45, 15	RCL FV
20	14	PMT
21	0	0
22	15	FV
23	13	PV
24	45, 1	RCL 1
25	40	+
26	10	÷
27	43, 33, 00	GTO 00

Example:

A machine with a cost of $40,000.00 is leased for 48 months.  Two advanced payments are required.  Interest rate is 10% (monthly periodic rate is 10%/12).  The residual value is estimated to be $15,000.

Input:

48 [STO] [ 0 ]   \\ term

2 [STO] [ 1 ]   \\ 2 advanced payments

10 [ENTER] 12 [ ÷ ] [STO] [ 2 ]  \\ interest rate

40000 [STO] [ 3 ]  \\ cost

15000 [STO] [ 4 ] \\ salvage value

Result:

[R/S]  -1249.30    (Each payment is $1,249.30.  Two advanced payments are $2,498.60).

Source:  HP 17bII+ Financial Calculator User’s Guide.  Hewlett Packard.  Edition 3:  2007

HP 12C: Net Present Value, Net Future Value, Net Utility Stream

Input:

Clear the registers/finance registers

Press [ g ] (GTO) 00 to get the pointer to line 00.  (000 for the HP 12C Platinum editions.  Remember, the Platinum editions have up to 400 steps and line numbers are in triple digits)

Store -1 in [ n ] (don’t worry, n is incremented in the main loop)

Store periodic interest rate in [ i ].

Store 0 in register 0  (0 [STO] [ 0 ]).  Register 0 is use for calculating NPV

Enter each cash flow one at a time, and press [R/S].

Ready to calculate:

Press [ g ] (GTO) 10  (or 010) to get the pointer to line 10. 

Press [R/S] to get NPV (net present value)

Press [R/S] to get NFV (net future value)

Press [R/S] to get NUS (net utility stream)

Program:

STEP	CODE	KEY
01	16	CHS  // main loop: input data
02	15	FV
03	45, 11	RCL n
04	1	1
05	40	+
06	11	n
07	13	PV
08	44, 40, 0	STO+ 0
09	43, 33, 0	GTO 00  // finish main loop
10	45, 0	RCL 0 // calculation part
11	31	R/S  // net present value
12	1	1
13	16	CHS
14	13	PV
15	0	0
16	14	PMT
17	15	FV
18	45, 0	RCL 0
19	20	*
20	31	R/S  // net future value
21	45, 0	RCL 0
22	1	1
23	16	CHS
24	14	PMT
25	0	0
26	15	FV
27	13	PV
28	10	÷
29	31	R/S  // net utility stream

Example:

Rate:  15%

Cash Flow #	Flow
0	-10,000.00
1	2500.00
2	3500.00
3	5000.00
4	5000.00

Input:

[ f ] CLEAR FIN, [ f ] CLEAR PRGM

-1 [ n ]  // do this on each new problem

0 [STO] [ 0 ]   // do this on each new problem

15 [ i ]

10000 [CHS] [R/S]

2500 [R/S]

3500 [R/S]

5000 [R/S]

5000 [R/S]

Results:

[GTO] 10  [R/S]:   NPV = 966.76

[R/S]:   NFV = 1690.88

[R/S]:   NUS = 338.62

Input slowly and carefully.

This blog entry is property of Edward Shore, 2016.