HP 20S and HP 21S: Qualifying Loan Amount (28:36 ratio)
Introduction
The program presented in today's blog entry will calculate the qualifying loan amount given the following:
* Loan's annual interest rate and term (in years)
* The borrower's monthly gross income
* The borrower's monthly non-property related debt (credit cards, auto loans, store bought appliances on credit, etc). Do not include utilities or phone bills.
* The estimated monthly property tax and insurance. For this program, combine the two amounts.
Before running the program, store the following amounts in the following registers:
R0: Monthly Income
R1: Monthly Debt
R2: Monthly Property Taxes and Insurance
R3: Annual Interest Rate
R4: Term
The down payment is not taken into consideration.
The result is the loan amount using the standard 28:36 ratio (stored in register R5). The 28:36 ratio is the guideline that the borrower spends no more than 28% of their income on housing expenses, and no more than 36% of their income on all debt service.
HP 20S and HP 21S Program: Qualifying Loan Amount
The key codes for most steps are the same. Lines where the key codes are different are noted, particularly the percentage function.
STEP KEY KEY CODE
01 LBL E 61, 41, E
02 FIX 2 51, 33, 2
03 RCL 0 22, 0
04 × 55
05 3 3
06 6 6
07 % HP 20S: 51,14 HP 21S: 51, 53
08 = 74
09 - 65
10 RCL 1 22, 1
11 = 74
12 STO 6 21, 6
13 RCL 0 22, 0
14 × 55
15 2 2
16 8 8
17 % HP 20S: 51,14 HP 21S: 51, 53
18 = 74
19 STO 7 21, 7
20 RCL 6 22, 6
21 INPUT 31
22 RCL 7 22, 7
23 X≤Y? 61, 42
24 SWAP 51, 31
25 STO 8 21, 8
26 RCL 2 22, 2
27 STO - 8 21, 65, 8
28 1 1
29 - 65
30 ( 33
31 1 1
32 + 75
33 RCL 3 22, 3
34 ÷ 45
35 1 1
36 2 2
37 0 0
38 0 0
39 ) 34
40 Y^X 14
41 ( 33
42 1 1
43 2 2
44 +/- 32
45 × 55
46 RCL 4 22, 4
47 ) 34
48 = 74
49 ÷ 45
50 ( 33
51 RCL 3 22, 3
52 ÷ 45
53 1 1
54 2 2
55 0 0
56 0 0
57 ) 34
58 = 74
59 × 55
60 RCL 8 22, 8
61 = 74
62 STO 5 21, 5
63 RTN 61, 26
Example
R0: Monthly Income = $4,485.00
R1: Monthly Debt = $375.00
R2: Monthly Property Taxes and Insurance = $126.83
R3: Annual Interest Rate = 5%
R4: Term = 30 years
Result: $207,288.60
Eddie
All original content copyright, © 2011-2018. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. Please contact the author if you have questions.
Introduction
The program presented in today's blog entry will calculate the qualifying loan amount given the following:
* Loan's annual interest rate and term (in years)
* The borrower's monthly gross income
* The borrower's monthly non-property related debt (credit cards, auto loans, store bought appliances on credit, etc). Do not include utilities or phone bills.
* The estimated monthly property tax and insurance. For this program, combine the two amounts.
Before running the program, store the following amounts in the following registers:
R0: Monthly Income
R1: Monthly Debt
R2: Monthly Property Taxes and Insurance
R3: Annual Interest Rate
R4: Term
The down payment is not taken into consideration.
The result is the loan amount using the standard 28:36 ratio (stored in register R5). The 28:36 ratio is the guideline that the borrower spends no more than 28% of their income on housing expenses, and no more than 36% of their income on all debt service.
HP 20S and HP 21S Program: Qualifying Loan Amount
The key codes for most steps are the same. Lines where the key codes are different are noted, particularly the percentage function.
STEP KEY KEY CODE
01 LBL E 61, 41, E
02 FIX 2 51, 33, 2
03 RCL 0 22, 0
04 × 55
05 3 3
06 6 6
07 % HP 20S: 51,14 HP 21S: 51, 53
08 = 74
09 - 65
10 RCL 1 22, 1
11 = 74
12 STO 6 21, 6
13 RCL 0 22, 0
14 × 55
15 2 2
16 8 8
17 % HP 20S: 51,14 HP 21S: 51, 53
18 = 74
19 STO 7 21, 7
20 RCL 6 22, 6
21 INPUT 31
22 RCL 7 22, 7
23 X≤Y? 61, 42
24 SWAP 51, 31
25 STO 8 21, 8
26 RCL 2 22, 2
27 STO - 8 21, 65, 8
28 1 1
29 - 65
30 ( 33
31 1 1
32 + 75
33 RCL 3 22, 3
34 ÷ 45
35 1 1
36 2 2
37 0 0
38 0 0
39 ) 34
40 Y^X 14
41 ( 33
42 1 1
43 2 2
44 +/- 32
45 × 55
46 RCL 4 22, 4
47 ) 34
48 = 74
49 ÷ 45
50 ( 33
51 RCL 3 22, 3
52 ÷ 45
53 1 1
54 2 2
55 0 0
56 0 0
57 ) 34
58 = 74
59 × 55
60 RCL 8 22, 8
61 = 74
62 STO 5 21, 5
63 RTN 61, 26
Example
R0: Monthly Income = $4,485.00
R1: Monthly Debt = $375.00
R2: Monthly Property Taxes and Insurance = $126.83
R3: Annual Interest Rate = 5%
R4: Term = 30 years
Result: $207,288.60
Eddie
All original content copyright, © 2011-2018. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. Please contact the author if you have questions.
