(12C) Actuarial Calculations

[Gamo]

Since HP 12C always calculate [n] as an Integer with rounding up result.
Program below help solve this problem to get result with fractional part and [n] can be input with fractional part by using the Actuarial Method.

*Program to calculate [i] and use fractional [n]

Code:


01  ,
02  0
03  1
04 STO 3
05  1
06 RCL 3
07  1
08  +
09 STO 1
10 RCL [n]
11 CHS
12 Y^X
13 STO 2
14  -
15 RCL 3
16  ÷
17 RCL 3
18 RCL 0
19  x
20  1
21  +
22  x
23 RCL [PMT]
24  x
25 RCL [PV]
26  +
27 RCL [FV]
28 RCL 2
29  x
30  +
31 RCL 2
32 RCL 1
33  ÷
34 RCL [n]
35  x
36 STO 4
37  1
38 RCL 2
39  -
40 RCL 3
41  ÷
42  -
43 RCL [PMT]
44 RCL 3
45  ÷
46  x
47 RCL [FV]
48 RCL 4
49  x
50  -
51  ÷
52 STO-3
53 ENTER
54 CHS
55 X≤Y
56 X<>Y
57 EEX
58 CHS
59  8
60 X≤Y
61 GTO 05
62 RCL 3
63 EEX
64  2
65  x
66 ENTER
67 STO [i]

Example of calculating interest rate required for growth:
A savings account has a balance of $1000. What annual interest rate is required to double the money in 5½ years?

Store 0 in register 0 for END mode; store 1 in register 0 for BEGIN mode.

0 STO 0 > 0 // Set END mode
1000 CHS [PV] > -1000.00
2000 [FV] > 2000.00
5.5 [n] > 5.50
0 [PM]T > 0.00
R/S > 13.43 // Answer

*Program to calculate [n]

Code:


01  1
02 RCL [i]
03  %
04 STO 2
05  +
06 STO 1
07 RCL 0
08 Y^X
09 RCL [PMT]
10  x
11 STO 3
12 RCL [FV]
13 RCL 2
14  x
15  -
16 RCL [PV]
17 RCL 2
18  x
19 RCL 3
20  +
21  ÷
22  LN
23 RCL 1
24  LN
25  ÷
26 STO [n]

Example of calculating compound interest:
A deposit of $150 is made each month in an account paying 6.5 percent, compounding monthly. How long will it take to accumulate $20,000? Assume END mode.

Store 0 in register 0 for END mode; store 1 in register 0 for BEGIN mode.

0 [STO] 0 > 0.00
6.5 g [i] > 0.54
0 [PV]
150 [CHS] [PMT] > -150.00
20000 [FV] > 20000.00
[R/S] > 100.63

This program is from HP Support website.
https://support.hp.com/us-en/document/bpia5043

Remark:
All calculations above work on HP 15C using TVM program from the Advance Functions Handbook.
For HP-12C these two program together use about 95 steps this can enhance 12C TVM functions.

Gamo