Mortgage math and qualifying ratios calculator, for Texas real estate exam practice.
Estimate loan amount, payment, PITI, front-end ratio, back-end ratio, and income needed. The goal is not lender approval. The goal is clean exam setup.
Mortgage qualifying math usually asks you to compare housing payment to income or housing plus debt to income. Keep monthly numbers with monthly numbers, and do not leave taxes or insurance out of the housing payment when the question includes them. Use the qualifying limits the stem gives you.
Subtract the down payment from purchase price before calculating payment.
Build the monthly housing payment from principal, interest, taxes, insurance, and HOA only if the stem includes it.
The front-end ratio compares housing payment to gross monthly income.
The back-end ratio includes housing plus recurring monthly debt.
Treat 28/36 as a practice default only. Actual loan products and lenders use different limits.
Estimate payment, LTV, and qualifying ratios.
Exam note: Texas exam stems usually give principal and interest or a payment factor. This calculator estimates P&I from rate and term so you can practice the ratio setup.
Qualifying ratios use the housing payment, not just principal and interest. Taxes, insurance, and HOA matter when the stem includes them.
The back-end ratio includes housing plus other monthly debt. The front-end ratio uses housing only.
A 28 percent ratio is 0.28 in the calculation. Use the ratio limits given in the stem.
A buyer can pass the front-end ratio and still fail the back-end ratio if car payments, credit cards, student loans, or other debt push the total too high.
Email the cheat sheet and this calculation.
Get the formula, trap reminders, and your current breakdown in one printable study note.
What this mortgage calculator is built to answer
Use it for Texas exam questions involving purchase price, down payment, loan amount, monthly housing payment, qualifying ratios, and gross monthly income. It shows each layer so the ratio setup does not get lost.
Why qualifying ratio questions get missed
Students often mix annual and monthly numbers, or they use principal and interest when the question is asking for the full monthly housing payment. The arithmetic is manageable. The category choice is the test.
Three mortgage patterns to know.
$400,000 price with 20 percent down
Do not use the purchase price as the loan amount after a down payment is given.
$2,576 housing payment and $9,200 gross monthly income
Front-end uses housing payment only.
$2,576 housing payment, $625 debt, $9,200 income
Back-end includes other recurring monthly debt.
Using principal and interest only
Mortgage qualifying questions often want the full housing payment. Taxes, insurance, and HOA dues can change the ratio.
Using annual income with monthly debt
Keep the time period consistent. Monthly payment belongs with monthly income.
Forgetting the back-end ratio
A buyer can look fine on housing alone and still be over the total-debt ratio.
What to review next.
How do you calculate a mortgage payment for exam math?+
The exam may give a payment factor, a table, or enough information to estimate payment. For qualifying questions, remember that the housing payment can include principal, interest, taxes, insurance, and HOA dues.
What is the front-end qualifying ratio?+
The front-end ratio is the housing payment divided by gross monthly income. It measures how much income goes to housing before other debts are included.
What is the back-end qualifying ratio?+
The back-end ratio is housing payment plus recurring monthly debt divided by gross monthly income. It is usually the stricter number when the buyer has other debt.
Is this calculator a lender approval tool?+
No. It is a study calculator for Texas real estate exam math. Actual mortgage approvals depend on lender guidelines, credit, assets, loan type, underwriting, and current rules.