A common rule of thumb says you can afford a home worth 2–3× your annual income. At $80,000/year that points to $160,000–$240,000. But in many US markets, the median home now sits above $400,000. The real question is not what a rule of thumb says — it is what your monthly cash flow can sustain. That requires understanding how much house you can afford based on your specific income, debts, and down payment.
The Two Rules Lenders Actually Use
The 28% front-end ratio
Lenders typically want your housing expenses — principal, interest, property taxes, and insurance (PITI) — to be no more than 28% of your gross monthly income. This is the "front-end" debt-to-income ratio.
Example: $80,000/year = $6,667/month gross. Maximum housing payment: $6,667 × 28% = $1,867/month.
The 36% back-end ratio (total DTI)
Your total debt payments — housing plus car payments, student loans, credit cards — should not exceed 36% of gross monthly income. Some conventional loans allow up to 43–45% back-end DTI if your credit score and reserves are strong.
Lenders calculate the maximum they will lend. You should calculate the maximum that lets you still save for retirement, maintain an emergency fund, and live comfortably. These are often very different numbers.
Affordability by Income Level
The table below shows estimated maximum housing budgets and home prices at 7% mortgage rate (30-year fixed), 10% down payment, and $300/month in property taxes + insurance. These are estimates — use the calculator below for your exact situation.
| Annual Income | Max Monthly Payment (28%) | Estimated Max Home Price |
|---|---|---|
| $50,000 | $1,167 | ~$155,000 |
| $60,000 | $1,400 | ~$185,000 |
| $80,000 | $1,867 | ~$250,000 |
| $100,000 | $2,333 | ~$315,000 |
| $120,000 | $2,800 | ~$380,000 |
| $150,000 | $3,500 | ~$480,000 |
| $200,000 | $4,667 | ~$640,000 |
Notice that at $80,000 income, the 28% rule supports a home around $250,000 — not the $240,000–$400,000 range you might see in "rules of thumb." The interest rate environment makes a large difference: at 4%, the same payment supports a much higher price.
What Drives the Home Price You Can Afford
| Factor | Effect |
|---|---|
| Down payment ↑ | Lower loan amount → higher price supported by same monthly payment |
| Interest rate ↑ | Higher monthly payment → lower home price supportable |
| Existing debt ↑ | Less room under 36% DTI → lower monthly budget for housing |
| Credit score ↑ | Lower rate offered by lender → higher price supportable |
| Loan term (15 vs 30 yr) | 15-year has higher payment but lower total cost; 30-year allows higher price at same monthly budget |
How interest rate changes affect affordability
On a $300,000 loan (30-year fixed), your monthly principal + interest payment is:
| Interest Rate | Monthly P&I | Total Interest Paid |
|---|---|---|
| 4% | $1,432 | $215,600 |
| 5% | $1,610 | $279,600 |
| 6% | $1,799 | $347,600 |
| 7% | $1,996 | $418,600 |
| 8% | $2,201 | $492,400 |
At 7% vs 4%, the same $300,000 loan costs you an extra $564/month and over $200,000 more in total interest. Rate matters enormously.
The Hidden Costs Buyers Underestimate
Your mortgage payment is only part of the real monthly cost of homeownership. Budget for:
- Property taxes: 0.5–2.5% of home value per year depending on state
- Homeowner's insurance: $1,200–$2,500/year typically
- PMI (if <20% down): ~0.5–1% of loan per year ($125–$250/month on $300K)
- HOA fees: $100–$700/month in many communities
- Maintenance: Budget 1–2% of home value annually ($3,000–$6,000 on a $300K home)
- Utilities: Often higher than renting — owned homes average $400–$600/month
Add these up and a $300,000 home can cost $3,000–$4,000/month in total carrying costs — not just the mortgage payment of ~$2,000.
Try the Mortgage Affordability Calculator
Key Takeaways
- The 28% rule: housing costs (PITI) should not exceed 28% of gross monthly income.
- The 36% rule: all debt payments combined should stay under 36% of gross monthly income.
- At $80,000/year income and 7% rates, the 28% rule supports roughly $250,000 in home price — not the $240K–$400K that popular rules of thumb suggest.
- Interest rate has a massive impact: a 3-point rate difference on $300K = $550/month more and $200K+ more in total interest.
- Don't forget: property taxes, insurance, PMI, maintenance, and utilities can add $1,000–$2,000/month on top of your mortgage payment.
For a complete overview of how compound interest, retirement planning, inflation, savings, and FIRE all connect, see our Investing Basics guide.