Mortgage Affordability Calculator
Lenders cap your debt-to-income ratio, not your dreams. Enter your income and obligations to see three affordability ranges — conservative 28%, standard 36%, and aggressive 43% DTI — with the estimated payment for each.
Your results
Charts & visualization
Affordable price range
The same income supports very different ceilings depending on how much may go to housing.
Back-end DTI at the recommended price
Debt-to-income ratio your estimated payment implies, against common lender cutoffs.
Every chart’s underlying numbers are available as text — use the “view as table” control under each chart.
How it works
The calculator works backward from the two ratios lenders actually apply:
- Front-end ratio — housing cost ÷ gross income. Conservative planning keeps it near 28%.
- Back-end ratio — housing plus all recurring debt ÷ gross income. Conventional loans typically allow up to 36%–45%; some programs stretch further.
For each ceiling (28%, 36%, 43%) it computes your maximum housing budget, subtracts existing debts, estimated taxes, insurance, HOA, and PMI, then solves for the largest loan whose payment fits. Because property tax scales with price, the solver iterates until the numbers converge.
Formula used
DTI%— debt-to-income ceiling being tested (28 / 36 / 43)Solve— largest loan whose P&I + tax + PMI fits the remaining budgetPrice— loan amount + your down payment
Example calculation
With $95,000 gross income ($7,917/month), $500 in existing debt payments, and $40,000 saved for down payment costs, the 36% back-end ceiling supports a total payment near $2,350 including tax, insurance, and PMI. That translates to a home price around $335,590 with a loan of roughly $295,590. The conservative 28% view caps the price closer to $250,625, while the aggressive 43% ceiling stretches toward $409,935.
Assumptions & limitations
- Gross (pre-tax) income is used, matching how lenders qualify borrowers.
- Property tax modeled as a percent of price; insurance entered directly.
- PMI assumed at 0.46% annually whenever the loan exceeds 80% of price.
- Closing costs, moving costs, maintenance, and utilities are not deducted from the affordability math.
- Qualifying for a maximum is not the same as being comfortable — that is why the conservative range exists.
Results are planning estimates based on your inputs and the stated assumptions — not financial advice or a loan offer. Verify important figures with your lender or advisor.
Frequently asked questions
What DTI do I need to buy a house?
There is no single number. Many conventional lenders prefer a back-end DTI at or below 36%, but approvals commonly happen up to 43%–45%, and some programs go higher with compensating factors. A lower DTI generally means better pricing and easier underwriting.
Why is this estimate different from simple “income × 3” rules?
Multipliers ignore interest rates, existing debts, taxes, and down payment size. Solving the actual payment equation produces a number tied to today’s rates rather than a stale heuristic.
Should I spend the maximum I qualify for?
Usually not. Qualification reflects the lender’s view of your budget, not yours. Childcare, commuting, retirement contributions, and income variability argue for staying below the ceiling — which is why the 28% range is shown alongside.
Does a bigger down payment increase affordability?
Yes, twice: it shrinks the loan needed for any given price, and dropping below 80% loan-to-value eliminates PMI, freeing more of the monthly budget for principal and interest.