(20S, 21S): Qualifying Loan Amount (28:36 ratio) - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Software Libraries (/forum-10.html) +--- Forum: General Software Library (/forum-13.html) +--- Thread: (20S, 21S): Qualifying Loan Amount (28:36 ratio) (/thread-11407.html) (20S, 21S): Qualifying Loan Amount (28:36 ratio) - Eddie W. Shore - 09-16-2018 10:31 PM 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. Program: Code: ``` 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``` Blog Entry: http://edspi31415.blogspot.com/2018/09/hp-20s-and-hp-21s-qualifying-loan.html