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
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