House Affordability Calculator

This calculator applies the standard 28/36 debt-to-income rule to your income, debts, and down payment to find a maximum affordable home price, then breaks the resulting monthly payment into principal, interest, taxes, insurance, and PMI across three risk levels.

For personal planning only — not financial advice.

Reviewed by CalculatorDrive Finance Editorial Board · Last updated

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Enter your income, debts, and down payment to see how much house you can afford and compare conservative, moderate, and aggressive scenarios.

The short answer

On $80,000 in annual income with $500 in monthly debts and $50,000 down, the standard 28/36 rule caps housing at $1,866.67 a month, supporting a maximum home price of about $264,905.67 at 6.5% over 30 years. That $50,000 down payment comes out to 18.9% of that price — just under 20% — which adds $125.36 a month in PMI to the payment.

Key takeaways

  • $80,000 income with $500 in monthly debts and $50,000 down supports a maximum home price of $264,905.67 at 6.5% over 30 years.
  • The two DTI limits — 28% of income for housing alone, 36% for housing plus all other debt — don't always agree; the calculator uses whichever caps the payment lower.
  • 18.9% down (just under the 20% PMI threshold) adds $125.36/month in PMI on top of principal, interest, taxes, and insurance.
  • Moving from the moderate to the aggressive scenario (28% to 32% of income) raises the max price from $264,905.67 to $296,846.54 — more house, but a thinner monthly cushion.

The 28/36 rule, and which limit actually binds

Lenders typically check two ratios at once: housing costs alone shouldn't exceed 28% of gross monthly income (the front-end ratio), and housing plus all other debt payments shouldn't exceed 36% (the back-end ratio). On $80,000 a year ($6,666.67/month) with $500 in existing monthly debt:

28% front-end limit: $6,666.67 × 0.28 = $1,866.67

36% back-end limit minus existing debt: ($6,666.67 × 0.36) − $500 = $1,900.00

Binding limit (the lower one): $1,866.67 — the front-end ratio

In this example the front-end ratio is the tighter constraint, but that flips for someone with more existing debt: a car payment or student loan large enough could push the back-end limit below the front-end one instead. The calculator always takes whichever number is smaller, since lenders enforce both simultaneously.

How close down payment sits to the PMI line

A $50,000 down payment sounds substantial, but against a $264,905.67 maximum home price, it works out to only 18.9% — just under the 20% threshold where private mortgage insurance drops off:

Down payment percentage: $50,000 ÷ $264,905.67 = 18.9%

PMI added to the monthly payment: $125.36

Because the calculator solves for the maximum price your budget supports, it can land just below common thresholds like 20% down without you asking for it. It's worth checking the down payment percentage in your results — a slightly smaller home price, or a bit more saved for closing, might clear the PMI line entirely.

Conservative, moderate, and aggressive compared

The same income and debts produce a different maximum price depending on how much of your budget you're willing to commit to housing:

Scenario Housing % of Income Monthly Budget Max Home Price
Conservative25%$1,666.67$238,819.01
Moderate28%$1,866.67$264,905.67
Aggressive32%$2,133.33$296,846.54

The spread between conservative and aggressive here is about $58,000 in home price for roughly $467 a month — a meaningful trade-off between buying power today and the cushion left over for savings, repairs, and the unexpected. The moderate scenario aligns with the standard 28/36 guideline lenders most commonly use.

Frequently Asked Questions

How do lenders determine how much house I can afford?

Lenders use debt-to-income (DTI) ratios — commonly the 28/36 rule. On $80,000 annual income with $500 in monthly debts and $50,000 down, that caps housing at $1,866.67 a month, which supports a maximum home price of about $264,905.67 at 6.5% over 30 years.

What counts as monthly debt for affordability?

Include car payments, student loans, credit card minimums, personal loans, and other recurring obligations. Do not include utilities, groceries, or discretionary spending. Underestimating debts leads to overestimating affordability.

Should I use gross or net income for affordability?

Lenders evaluate gross (pre-tax) income, which is what this calculator uses. Your take-home pay is lower after taxes and deductions, so leave room in your budget beyond the maximum DTI threshold.

How does down payment affect affordability?

A larger down payment reduces the loan amount and monthly payment, which can increase the home price you qualify for. On the $264,905.67 example, $50,000 down works out to 18.9% — just under the 20% PMI threshold — adding $125.36 a month in PMI that a slightly larger down payment would remove.

Is the maximum affordable price a loan approval amount?

No. Approval depends on credit score, employment history, assets, and the specific property. This tool provides educational estimates — not a pre-approval or financial advice. Consider working with a lender before making an offer.

How do I use this house affordability calculator?

Enter annual household income, monthly debt payments, and available down payment. Set interest rate, loan term, property tax rate, insurance rate, and HOA fees, then click Calculate to see your maximum affordable home price and monthly payment across three DTI scenarios.

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