Calculated Industries Qualifier Plus IIX and HP 12C: Maximum Loan Amount and Allowable Payment

Calculated Industries Qualifier Plus IIX and HP 12C:  Maximum Loan Amount and Allowable Payment

Introduction

Given the following:

*  term of the loan, in years

*  the amount mortgage

*  annual interest rate

*  monthly expenses including property tax and mortgage interest

The following are calculated:

*  payment, including PITI

*  minimum required income

*  maximum allowable (other) debt

Assumptions:

*  The standard 28:36 ratio is used (28% for PITI, 36% for PITI and other monthly debts)

*  Payments are made at the end of each month

Both of the above parameters are can be changed but the program uses these assumptions.

Formulas (as determined by verifying examples):

PITI =  PMT + monthly property insurance + monthly property tax

Minimum Required Income:

RI = (PITI * 12) / 0.28 

Maximum Allowable (Other Debt): (uses RI from Required Income)

MA = (RI * 0.36) / 12 - PITI

Calculated Industries Qualifier Plus IIx:  Key Strokes

Note:  The IIx is a predecessor of the Qualifier Plus IIIx, however I believe the key strokes should be the same.  

Inputs:

annual interest [ Int ]

number of years [ Term ]

amount to be financed [ L/A ]   ([Loan Amt] on the IIIx)

annual property tax [ Tax ]

annual property insurance [ Ins ]

Alternate to amount to be financed:

total price [ Price ],  down payment as a percent of the price [ Dn Pmt ]

Output:

[ Pmt ] to display payment

[ Pmt ] again to display PITI

[ Qual 1 ] to display the required minimum income

[ Qual 1 ] again to display the maximum allowable (other) debt

HP 12C: Program

Input Instructions: 

annual interest [ g ] (12÷)

number of years [ g ] (12×)

amount to be financed [ PV ]   

0 [ FV ]

monthly combined property tax and insurance [ R/S ]

Alternate:  

annual property tax [ ENTER ] annual property insurance [ + ] 12 [ ÷ ] [ R/S ]

Output:

to display payment

[ R/S ] again to display PITI

[ R/S ] again to display the required minimum income

[ R/S ] again to display the maximum allowable (other) debt

Step # :  Key Code:  Key

01 : 44,0         :    STO 0

02 : 14         :        PMT

03 : 14         :        PMT

04 : 31         :        R/S

05 : 45, 0 : RCL 0

06 : 16         : CHS

07 : 40         : +

08 : 44, 1 : STO 1

09 : 31         : R/S

10 : 48         : .

11 : 2         : 2

12 : 8         : 8

13 : 10         : ÷

14 : 44,3         : STO 3

15 : 1         : 1

16 : 2         : 2

17 : 16         : CHS

18 : 20         : ×

19 : 44,2         : STO 2

20 : 31         : R/S

21 : 45,3         : RCL 3

22 : 16         : CHS

23 : 3         : 3

24 : 6         : 6

25 : 25         : %

26 : 45,1         : RCL 1

27 : 40         : +

28 : 44,3         : STO 3

29 : 43,33,00 : GTO 00

Examples

Example 1:

annual interest:  4.7%

number of years: 30

amount to be financed:  305,000.00

annual property tax: 0.00

annual property insurance: 0.00

Results:

payment:  1,581.85

PITI:  1,581.85

required minimum income:  67,793.37

maximum allowable (other) debt: 451.96

Example 2:

annual interest:  5%

number of years: 30

amount to be financed:  235,000.00

annual property tax: 1,000.00

annual property insurance: 105.00

(monthly combined tax and insurance:  92.08)

Results:

payment:  1,261.53

PITI:  1,353.61

required minimum income:  58,012.03

maximum allowable (other) debt: 386.75

Eddie

All original content copyright, © 2011-2021.  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. 

HP 20S and HP 21S: Qualifying Loan Amount (28:36 ratio)

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.