A Program for Converting Interest and Discount Rates on HP12C Message #1 Posted by MacDonald Phillips on 3 May 2008, 10:21 a.m.
The following program will convert any interest or discount rates to any other interest or discount rate, including continuous rates.
001 STO 0
002 RDOWN
003 STO 1
004 g x=0
005 g GTO 015
006 EEX
007 2
008 x (times)
009 / (divide)
010 1
011 +
012 RCL 1
013 Y^x
014 g GTO 020
015 RDOWN
016 EEX
017 2
018 /
019 g e^x
020 RCL 0
021 g x=0
022 g GTO 033
023 1/x
024 Y^x
025 1
026 
027 RCL 0
028 EEX
029 2
030 x
031 x
032 g GTO 000
033 RDOWN
034 g LN
035 EEX
036 2
037 x
038 g GTO 000
To use the program simply enter the interest rate, it's compounding periods, and the compounding periods you want to convert to and press R/S. If you are converting from or to a discount rate, enter the compounding period as a negative number. If you are coverting from or to a continous rate, enter 0 as the compounding periods.
Example 1: 10% interest rate, compounded monthly to the equivalent rate compounded semianually.
10 ENTER
12 ENTER
2 R/S
Ans: 10.21066220
Example 2: 8% discount rate, compounded monthly to the equivalent interest rate compounded quarterly.
8 ENTER
12 CHS ENTER
4 R/S
Ans: 8.107864000
Example 3: 7% interest rate, compounded continuously, to the equivalent interest rate compounded monthly.
7 ENTER
0 ENTER
12 R/S
Ans: 7.020456000
Don Phillips
don.phillips@gmail.com
