The bank pre-approved you for a $600,000 mortgage.
You're excited. You start looking at $600,000 houses.
Here's the problem: You can't actually afford a $600,000 house.
The bank's approval is based on what you can borrow, not what you should borrow.
There's a massive difference.
The Lender's Math vs Your Math
What lenders approve you for:
Your total monthly debt payments (mortgage + car + student loans + credit cards) can be up to 43% of your gross income.
This is called the debt-to-income ratio (DTI).
Example:
You make $8,000/month gross income.
43% DTI = $3,440/month maximum total debt payments
If you have $500/month in other debts:
- Maximum mortgage payment: $2,940/month
- After property tax and insurance, this qualifies you for a ~$350,000 mortgage at 6.5% (20% down)
The bank will approve you for a $350,000 mortgage.
What you can actually afford safely:
Your housing payment (mortgage + taxes + insurance) should be 28% of gross income or less.
28% of $8,000 = $2,240/month maximum housing payment
You should actually buy a house with a $2,240 payment, not $2,940.
That's about a $265,000 mortgage, not $350,000.
The bank will approve you for 31% more house than you can comfortably afford.
The 28/36 Rule
The safe guideline financial advisors use:
28% Rule: Housing costs ≤ 28% of gross monthly income
36% Rule: Total debt payments ≤ 36% of gross monthly income
Housing costs include:
- Mortgage principal and interest
- Property taxes
- Homeowners insurance
- HOA fees (if applicable)
- PMI (if down payment <20%)
Total debt includes:
- All housing costs above
- Car payments
- Student loans
- Credit card minimum payments
- Personal loans
Example breakdown:
Gross income: $8,000/month
28% housing: $2,240 max
36% total debt: $2,880 max
If you have $400/month car payment and $200/month student loans:
- Housing budget: $2,240
- Other debt: $600
- Total debt: $2,840 (under the $2,880 limit) ✓
You're within safe limits.
The Catch: 28% Is Measured Against Gross Pay
The 28/36 rule uses gross income, your pay before taxes. But you pay your mortgage with take-home pay.
At $100,000 a year:
- Gross monthly income: $8,333
- 28% of gross: $2,333/month for housing
- Take-home after taxes: about $6,000/month
That $2,333 is 39% of the money that actually lands in your account.
Spending nearly 40% of your paycheck on housing leaves little room for everything else. Treat 28% of gross as a ceiling, not a target.
Real Income Examples
Here's what you can actually afford at different income levels:
| Annual Income | Monthly Gross | 28% Housing | Affordable Mortgage* |
|---|---|---|---|
| $60,000 | $5,000 | $1,400 | ~$165,000 |
| $80,000 | $6,667 | $1,867 | ~$220,000 |
| $100,000 | $8,333 | $2,333 | ~$280,000 |
| $120,000 | $10,000 | $2,800 | ~$335,000 |
| $150,000 | $12,500 | $3,500 | ~$415,000 |
*Loan amount at 6.5% for 30 years with 20% down. The 28% covers principal, interest, property tax (1.5% of the home's value a year), and insurance (0.5% a year).
Notice something?
At $100,000/year income:
- Lenders might approve (43% of gross): ~$425,000 mortgage
- You should actually buy: ~$280,000 mortgage
That's a $145,000 difference.
The Hidden Costs No One Tells You
When calculating affordability, most people forget these costs:
1. Property Taxes
Varies by location, but typically 1-2% of home value annually.
$400,000 house × 1.5% = $6,000/year = $500/month
2. Homeowners Insurance
$1,000-$3,000/year depending on location and home value.
Average: ~$150/month
3. HOA Fees
If buying a condo or planned community: $200-$500+/month
4. Maintenance
Rule of thumb: 1% of home value per year.
$400,000 house = $4,000/year = $333/month
New roof, HVAC replacement, plumbing issues—they happen.
5. PMI (if down payment <20%)
0.5-1% of loan amount annually.
$320,000 loan × 0.75% = $2,400/year = $200/month
Total monthly cost example:
$400,000 house, $320,000 mortgage at 6.5%:
- Mortgage payment: $2,024
- Property taxes: $500
- Insurance: $150
- HOA: $250
- Maintenance fund: $333
- PMI: $200
True monthly cost: $3,457
Most people only budget for the $2,024 mortgage payment.
What Lenders Don't Care About
The bank's 43% DTI approval doesn't account for:
❌ Your retirement savings
❌ Your kids' college fund
❌ Your emergency fund contributions
❌ Groceries, gas, utilities
❌ Childcare costs
❌ Healthcare expenses
❌ Actually having a life (vacations, hobbies, etc.)
A bank will approve you for a payment that leaves you with no breathing room.
You'll make the payments technically, but you'll be house-poor—no savings, no fun money, stressed about every unexpected expense.
The House-Poor Trap
Scenario:
You make $100,000/year ($8,333/month gross, ~$6,000 take-home after taxes).
Bank approves you for $3,583/month total debt (43% DTI).
You buy a house with a $3,200/month total housing cost.
Your budget:
- Take-home pay: $6,000
- Housing: $3,200
- Remaining: $2,800
Now pay for:
- Groceries: $600
- Gas/transportation: $300
- Utilities: $200
- Internet/phone: $150
- Healthcare: $300
- Remaining: $1,250
That's for everything else: retirement, emergency fund, kids, entertainment, clothes, repairs, everything.
You're house-poor. One emergency away from credit card debt.
The 25% Take-Home Rule: A Target You Can Live With
Here's a simpler, safer rule:
Keep your total housing cost at or below 25% of your take-home pay.
"Total housing cost" means everything:
- Mortgage principal and interest
- Property taxes
- Homeowners insurance
- HOA fees
- A maintenance budget (1% of the home's value per year)
Example: $100,000 salary, about $6,000/month take-home
25% of $6,000 = $1,500/month for total housing.
With 20% down at 6.5% on a 30-year loan, that covers about a $200,000 home:
- Mortgage (principal and interest) on a $159,000 loan: $1,004
- Property tax (1.5% a year): $248
- Insurance (0.5% a year): $83
- Maintenance (1% a year): $165
- Total: $1,500
How much room do you want?
- Conservative: 25% of take-home, about a $200,000 home
- Moderate: 30% of take-home, about a $238,000 home
- Aggressive: 35% of take-home (not recommended), about a $278,000 home
Those numbers look low next to what lenders approve. That's the point. The gap between the bank's number and yours is money you keep for savings, retirement, and the rest of your life.
These prices assume 20% down, a 6.5% rate, and no HOA. Put in your own numbers with the mortgage calculator.
Where You Live Changes Everything
The 25% rule works well in affordable markets. Most people don't live in one.
Median home prices (2024, approximate):
- San Francisco: $1.5M
- Los Angeles: $900K
- Seattle: $800K
- Denver: $600K
- Austin: $550K
- Raleigh: $425K
- National median: $420K
To buy the national median home with 20% down and stay within the 25% rule:
- $336,000 loan at 6.5%: $2,124/month
- Plus about $400 property tax, $200 insurance, and $350 maintenance
- Total housing cost: $3,074/month
- Take-home pay needed: about $12,300/month
- Gross income needed: about $197,000/year (assuming 25% goes to taxes)
The median American household earns about $80,000.
That's why so many buyers stretch. If prices in your market don't fit the rule, don't ignore the math. Change something you control: a cheaper area, a smaller home, a bigger down payment, or more time to save.
The Better Way to Calculate
The 25% rule is a quick check. If you have big fixed commitments like childcare, other debt, or aggressive saving goals, build your housing budget from the bottom up instead:
Step 1: Start with take-home pay
Not gross income—actual money that hits your account.
Step 2: Subtract fixed expenses
- Retirement contributions (15% minimum)
- Emergency fund contribution
- Other debt payments
- Insurance
- Childcare
Step 3: What's left is your budget for housing + living
Housing should be 25-30% of what remains, MAX.
Example:
Take-home: $6,000/month
- Retirement (15%): $900
- Emergency fund: $300
- Car payment: $400
- Other expenses: $1,200
Remaining: $3,200
Housing budget: 30% of $3,200 = $960/month
Wait—that's way less than 28% of gross!
Yes. Because this is what you can actually afford while building wealth.
Buy Less House, Build More Wealth
Here's the math nobody shows you. Compare two houses, both bought with 20% down at 6.5%:
Option A: The maximum house, $555,000
- Total monthly cost (mortgage, taxes, insurance, maintenance): $4,194
Option B: A modest house, $250,000
- Total monthly cost: $1,889
The difference is $2,305 a month.
Invest that difference for 30 years at a 7% average annual return and it grows to about $2.8 million.
After 30 years, both mortgages are paid off:
- Option A: a $555,000 house
- Option B: a $250,000 house plus about $2.8 million invested
That's more than five times the wealth, and Option B needed $61,000 less for the down payment.
This ignores home appreciation, which helps the bigger house somewhat, but not nearly enough to close that gap.
The Down Payment Decision
20% down is ideal because:
- No PMI ($200+/month savings)
- Better interest rates
- Smaller loan = less interest overall
- More equity from day 1
But 20% down might not be realistic:
On a $400,000 house: $80,000 down payment
Alternatives:
5% down: $20,000
- PMI required: ~$200/month extra
- Saves you ~$60,000 in cash upfront
- Lets you buy sooner (while saving the rest)
3% down (FHA): $12,000
- PMI for life of loan (or until you refinance)
- Lower credit requirements
- Faster entry to homeownership
The trade-off:
Waiting to save 20% means:
- Prices might rise (offsetting PMI savings)
- Rent payments continue (not building equity)
- But you have more cash cushion
Buying with 5% down means:
- Building equity now
- Locking in current prices
- But paying PMI until you hit 20% equity
There's no universal right answer.
The Decision Framework
Can you afford this house?
Ask these questions:
✅ Is the total monthly housing cost ≤28% of gross income?
✅ Is the total housing cost, including maintenance, no more than 25-30% of take-home pay?
✅ Will you have 6 months emergency fund AFTER down payment and closing costs?
✅ Do you have a separate home maintenance fund ($10,000+) on top of that?
✅ Can you still save 15% for retirement?
✅ Is your total debt (housing + other) ≤36% of gross income?
✅ Could you handle a $5,000 emergency repair without going into debt?
✅ If your rate is adjustable, could you still afford the payment if it rose 2%?
If all 8 are YES → You can afford it
If any are NO → The house is too expensive
What to Do If You're House Shopping Above Your Budget
Options:
1. Look at cheaper houses
Obvious but often resisted. Buying less house means less stress.
2. Increase your down payment
Borrow less = smaller monthly payment.
3. Wait and save more
Increase income, save aggressively, buy in 1-2 years.
4. Consider a 15-year mortgage
Wait—higher payment? Yes, but you're forced to buy a cheaper house, and you'll own it in 15 years instead of 30.
If you're approved for $500,000 at 30 years, you might afford $380,000 at 15 years. Less house, but debt-free much faster.
5. Buy with a partner/spouse
Dual income = higher budget. But make sure both incomes are stable.
The Final Rule
The house you can afford is not the house the bank approves.
Lenders maximize their profit. They want you to borrow as much as possible.
You maximize your life. You want to borrow what keeps you comfortable, not stressed.
The bank will approve you for broke. Don't let them.
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Calculate Your Real Budget
Use the Mortgage Calculator to:
- See your exact monthly payment at different home prices
- Include taxes, insurance, and PMI in your calculation
- Compare 15-year vs 30-year terms
- Find the home price that fits your actual budget
Start with 25% of your take-home pay, and make sure you're under the 28% ceiling, before you start shopping.
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