How the affordability scenario is derived
This calculator works backward from a budget ratio that you choose. It is a planning scenario—not a lender underwriting limit and not a statement that a given payment is affordable for you.
The model multiplies gross monthly income by the debt-budget ratio you enter, then subtracts other monthly debt payments and the non-principal-and-interest housing costs you enter. The remaining amount becomes the modeled principal-and-interest budget. The calculator then reverses the fixed-payment formula to estimate a loan amount and adds the entered down payment to show an illustrative purchase price.
Gross monthly income × chosen ratioThe ratio is your scenario input, not a program threshold.
Debt budget − other debt − taxes/insurance/HOA/MIOnly a positive remainder can support modeled principal and interest.
Present value of the P&I budget at entered rate and termThe down payment is then added to derive an illustrative purchase price.
Start with reliable gross monthly income, not take-home pay, if you want the ratio to be internally consistent.
Choose a debt-budget ratio deliberately; do not assume the default represents approval guidance.
Enter other debt and recurring housing costs rather than leaving them at zero.
Run a lower-ratio or higher-rate stress case before treating the output as a planning ceiling.
Best used for
- Exploring a conservative purchase-price range
- Seeing how debt payments reduce a housing budget
- Testing the impact of a different rate, down payment or budget ratio
What this tool does not answer
- It does not apply lender-specific income, debt or reserve rules.
- It does not decide what payment is personally comfortable after taxes and living expenses.
- Closing costs and product-specific mortgage-insurance rules are separate from this purchase-price scenario.
How to read a sample result
Illustrative example: $10,000 of gross monthly income, a self-selected 36% total-debt budget, $500 of other debt and $600 of other housing costs leave $2,500 for modeled principal and interest. At 6% for 360 months, that supports about $416,979 of modeled loan amount; adding a $60,000 down payment gives an illustrative purchase price of about $476,979.
The methodology below explains how this calculator treats the inputs and assumptions. Replace the sample values with your own planning figures. Results are estimates, not quotes, approvals, disclosures or recommendations.
Inputs and units
Gross monthly income, chosen total-debt ratio, other debt, ownership costs, rate, term and down payment. All currency entries are U.S. dollars. Percentage fields take a number such as 6 for six percent, not 0.06. Repayment terms marked in months use whole months; horizons marked in years use whole years.
Calculation workspace
Enter your own figures in the calculator above. The starting values are examples only. No personal identifiers are needed to run a scenario.
How to interpret the result
Read every result together with the assumptions you entered. Changing an input changes the scenario, not product availability. Displayed amounts are rounded for readability.
Assumptions and limitations
The chosen ratio is a user assumption, not a lender qualification limit. The result excludes costs not entered and is not approved purchasing power.
Review more than one scenario
Run a base case and then change one uncertain input at a time. Compare a shorter holding period, a higher cost or a different repayment term where those inputs are supported. Record which costs have not been entered. A precise-looking number can still rest on uncertain assumptions.
Invalid inputs and error recovery
If an input is missing or outside the calculator’s supported range, the page will ask you to correct it. Use negative values only in fields that explicitly allow them. A calculation error is not a credit decision.
Model documentation
The calculator methodology explains the inputs, assumptions and supported models. Use the result for planning and compare it with the provider’s written terms and applicable disclosures before making a decision.
Choose a product for your calculation
Use these comparisons for planning; final eligibility, pricing and terms are set by the provider.
Program references and comparison sources
CFPB: Loan Estimate explainer — Comparison of covered mortgage disclosures, cash to close, points, lender credits and monthly costs.
CFPB: Understand the different kinds of loans available — Loan structures, terms and repayment risks; not provider-specific eligibility.
Check the linked source for its effective date and applicable scope. A source link is not a lender partnership or an individual offer.