Loan Affordability Calculator
What loan amount can you actually afford? Enter income, debt, rate, and term; the tool back-solves for the maximum loan within lender DTI limits.
About the Loan Affordability Calculator
The Loan Affordability Calculator answers the most important question before house hunting or applying for a loan: how much can you realistically afford? It uses real lender math - debt-to-income ratios, front-end and back-end caps, and your full debt picture - to back-solve the maximum loan that would actually be approved at your income and rate.
The calculator applies the 28/36 rule by default (28% of gross income on housing, 36% on total debt) and lets you tighten or relax those caps. It accounts for property tax, insurance, HOA, and existing debt obligations like car loans, student loans, and credit-card minimums - the same line items a mortgage underwriter examines.
Common use cases
- Set a realistic price ceiling before house hunting
- Pre-qualify yourself before formal mortgage application
- See how paying off a car loan changes your max approved mortgage
- Compare maximum loan at different rate scenarios
Tips for accurate results
Never borrow the maximum a lender will approve. The 28/36 caps are regulatory ceilings, not personal targets - living near them leaves zero margin for car repairs, medical bills, job changes, or the unexpected. Most financial planners recommend staying at 70-80% of your maximum approval, which keeps your back-end DTI under 30%.
Privacy & data handling
The Loan Affordability Calculator runs entirely in your browser. Nothing you enter is uploaded, logged, or shared with third parties - the math happens locally and your inputs disappear when you close the tab. There is no signup, no email collection, and no daily-use limit.
What is debt-to-income ratio (DTI)?
DTI is the percentage of your gross monthly income that goes to debt payments. Front-end DTI counts only housing costs; back-end DTI counts all minimum debt payments (housing + cards + auto + student loans). Most conventional mortgage lenders cap back-end DTI at 43-45%, with 36% being the safer guideline.
How much house can I afford?
A common rule is the 28/36 rule: spend no more than 28% of gross income on housing (front-end DTI) and no more than 36% on total debt. For $100k income that's ~$2,333/mo on housing and ~$3,000/mo on all debt. The tool computes the maximum loan that keeps you under these caps at your chosen rate and term.
Does the calculator account for property tax and insurance?
Yes - affordability rules use the full PITI payment (principal, interest, tax, insurance), not just principal & interest. The tool subtracts your estimated tax + insurance from your housing budget before back-solving the loan amount, so the answer reflects what a lender would actually approve.
Should I borrow the maximum I qualify for?
Almost never. Lenders approve to the top of regulatory caps; living near the cap leaves no margin for car repairs, medical bills, or job changes. Most planners suggest staying at 25-28% of gross income on housing and keeping back-end DTI under 30%, which means borrowing 70-80% of what you "qualify" for.
How does down payment affect affordability?
A larger down payment reduces both the loan size and the monthly payment, freeing room under DTI caps. It also typically lowers your rate (more equity = less risk to the lender) and can remove PMI entirely if you hit 20%. The tool shows side-by-side: same income, different down payments, different max loan.
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