HP 12C Programming III: Refinancing, Advance Payments in a Lease, NPV, NFV, NUS
HP 12C Programming Part I: Modulus, GCD,
PITI
HP 12C Programming Part
II: Weekday Number, Gross Up Calculation
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withdrawn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.