Home Mortgage Calculator

How to Determine How Much Home You Can Afford

1. Start with your gross monthly income: Enter your combined household gross income — before taxes. Multiply by 28% to find the maximum PITI payment your lender will typically approve. Subtract your estimated monthly property tax and insurance to arrive at your maximum principal-and-interest budget.
2. Determine your realistic down payment: Enter the amount you can put down without depleting your emergency fund. Remember: you need closing costs (2–5% of loan) on top of the down payment. If your down payment is under 20%, add the estimated PMI to your monthly cost projection.
3. Back-calculate the maximum home price: With your maximum P&I payment and current interest rates, the calculator solves for the loan amount you can sustain. Add your down payment to find the corresponding maximum home price — this is your true shopping ceiling.
4. Add all non-mortgage monthly costs: Input the property tax rate for your target area (check the county assessor's website), homeowner's insurance estimate, and any known HOA fees. These inflate your effective monthly cost and may lower your viable price range.
5. Stress-test with rate increases: Enter the same scenario at 0.5% and 1.0% above your current rate quote — rates can change between pre-approval and closing. Confirm you can afford the payment even if rates rise before you lock.

Real-World Use Case

Marcus and Priya are first-time buyers with a combined gross income of $115,000/year ($9,583/month) and $68,000 saved. Applying the 28% rule, their maximum PITI payment is $2,683/month. After subtracting estimated property tax of $525/month and insurance of $140/month, their maximum principal-and-interest payment is $2,018/month. At a 7.25% rate on a 30-year loan, that P&I budget supports a loan of approximately $290,000. With $55,000 going to the down payment (keeping $13,000 for closing costs and reserves), they can target homes priced up to $345,000 — not the $420,000 their pre-approval letter authorized. The calculator also shows that at $345,000 with 15.9% down, they'll pay approximately $170/month in PMI until they reach 20% equity around year 4, making their true all-in monthly cost $2,853/month, well within their budget and their debt-to-income limits.

Best Practices for First-Time Homebuyers

• Calculate your personal affordability ceiling, not just lender qualification: Lenders approve based on gross income ratios, but your mortgage gets paid from net (take-home) income after taxes, retirement contributions, and health insurance. A payment that consumes 28% of gross may consume 38–42% of your actual take-home pay — use after-tax income to sanity-check whether the payment is truly comfortable.
• Budget for the down payment plus closing costs plus three months of reserves: Many first-time buyers drain their savings entirely into the down payment, leaving nothing for closing costs ($8,000–$18,000 on a $350,000 purchase) or unexpected repairs in the first year. Lenders also look favorably on reserve funds — two to three months of mortgage payments in savings strengthens your application and protects you post-close.
• Run the PMI break-even calculation before increasing your down payment to 20%: If reaching 20% down requires delaying your purchase by 18–24 months, calculate whether the rent you'd continue paying during that delay exceeds the total PMI you'd pay by buying now with less down. In high-rent markets, buying with 10–15% down and paying PMI briefly often outperforms waiting to save the full 20%.
• Use the calculator to model property tax rate differences across neighborhoods: Property tax rates vary dramatically — a $375,000 home in a high-tax suburb may generate a $600/month tax bill while the same price in a neighboring low-tax district costs $350/month. This $250/month difference is worth $45,000 in additional loan affordability at equivalent payment levels.
• Test the impact of a larger down payment on PMI removal timing: Compare a 10% down scenario against a 15% down scenario — the extra 5% may eliminate 3–4 years of PMI payments, often exceeding the investment return you'd earn keeping that money in savings. The calculator's amortization schedule shows exactly when the 20% equity threshold is crossed.

Performance & Limits

• Home price range: Calculates affordability for homes from $50,000 starter properties to $5,000,000+ luxury purchases — covers the full spectrum of first-time buyer markets across the US.
• PMI calculation included: Automatically estimates PMI when the down payment is below 20%, applies lender-typical rates of 0.5%–1.5% of loan amount annually, and identifies the calendar month when PMI removal eligibility is reached based on the amortization schedule.
• Full PITI output: Displays the complete monthly payment broken down into principal, interest, property tax escrow, homeowner's insurance escrow, HOA, and PMI so each cost component is transparent.
• Debt-to-income visualization: Input your gross monthly income to see your housing expense ratio and total DTI ratio overlaid on lender approval thresholds — instantly confirms whether a scenario qualifies under 28/36 guidelines.
• Down payment sensitivity: Run multiple scenarios by changing the down payment amount to compare how each option affects monthly payment, total interest, PMI duration, and the equity timeline.

Common Mistakes to Avoid

• Calculating affordability from the monthly payment alone: Many first-time buyers find a monthly payment they can manage and work backward to a home price — without accounting for property tax, insurance, maintenance, or the opportunity cost of locking up a large down payment. Always calculate the total cost of ownership, not just the P&I figure.
• Treating a pre-approval letter as a spending target: A lender's pre-approval amount is a ceiling, not a recommendation. Banks are incentivized to lend the maximum you qualify for — it is your job to determine a payment you can sustain through job changes, income dips, and rising household expenses over a 30-year horizon.
• Ignoring the closing cost timeline: Closing costs of 2–5% of the loan amount are due at settlement, not rolled into the monthly payment (in most cases). Buyers who reach closing without adequate closing cost funds either pay higher rates to roll costs into the loan, scramble for seller concessions, or fail to close entirely.
• Comparing home affordability in different locations without adjusting for tax rates: Property tax rates range from under 0.5% in Hawaii and Alabama to over 2.0% in New Jersey and Illinois. A $400,000 home in a 0.5% tax state costs $167/month in taxes; the same home in a 2.1% tax state costs $700/month — a $533/month difference that dramatically changes your affordable price range.

Privacy & Security

• All calculations run locally in your browser: Your income, home price, down payment, and debt figures never leave your device — no data is sent to any server at any point during calculation.
• No lender data sharing: Your mortgage scenario inputs are not shared with banks, lenders, lead generation services, or any third parties — this tool does not generate mortgage leads.
• No registration or personal information required: Use the full calculator including amortization schedules and affordability analysis without creating an account or providing your name, email, or contact information.
• Session-isolated inputs: All inputs are cleared automatically when you close or navigate away from the page — nothing is persisted in cookies, localStorage, or browser history.