How Much House Can I Afford? A Complete Home Buying Guide

Buying a home is likely the largest financial decision you will ever make. Knowing how much house you can afford before you start shopping prevents the heartbreak of falling in love with a home outside your budget — and the financial stress of being "house poor."

The 28/36 Rule (Lender Standard)

Lenders use this guideline to determine how much they will lend you:

• 28% Front-end ratio: Housing costs (mortgage PITI) should not exceed 28% of gross monthly income
• 36% Back-end ratio: Total debt payments (housing + all other debts) should not exceed 36% of gross monthly income

Example:

Household gross monthly income: $8,000

• Max housing cost: $8,000 × 0.28 = $2,240/month
• Max total debt: $8,000 × 0.36 = $2,880/month
• Available for other debt: $2,880 − $2,240 = $640/month

What Is Included in "Housing Cost" (PITI):

• Principal: The loan amount repayment
• Interest: Cost of borrowing
• Taxes: Property taxes (typically 1–3% of home value annually)
• Insurance: Homeowner's insurance

Plus: PMI (if down payment < 20%), HOA fees, and maintenance costs.

Debt-to-Income Ratio (DTI)

DTI = Total monthly debt payments ÷ Gross monthly income × 100

How Down Payment Affects Affordability

A 20% down payment eliminates PMI, which saves $100–$300 per month and approximately $30,000+ over the life of the loan.

Hidden Costs of Homeownership

Many first-time buyers forget these costs:

• Closing costs: 2–5% of purchase price ($8,000–$20,000 on a $400,000 home)
• Property taxes: 1–3% of home value annually
• Maintenance and repairs: 1–2% of home value annually ($4,000–$8,000/year)
• Homeowner's insurance: $1,000–$3,000/year
• Utilities: Often higher than apartments
• HOA fees: $100–$500+/month
• Furniture and appliances: Easily $10,000+ for a new home
• Moving costs: $1,000–$5,000

The Affordability Formula

Maximum home price = (Annual income × 3) to (Annual income × 5)

Conservative: 3× annual income

Moderate: 4× annual income

Aggressive: 5× annual income (only with large down payment)

Example: $100,000 annual income

• Conservative: $300,000 home
• Moderate: $400,000 home
• Aggressive: $500,000 home

Step-by-Step: Calculate Your Affordability

1. Calculate gross monthly income

2. List all monthly debt payments (car, student loans, credit cards)

3. Calculate maximum monthly housing payment: Income × 0.28

4. Subtract existing debts from Income × 0.36

5. The lower of step 3 and step 4 is your max housing payment

6. Estimate taxes, insurance, PMI (typically 25–35% of payment)

7. Back into loan amount using current interest rates

8. Add down payment for estimated home price

FAQ: Home Affordability

Housing costs should not exceed 28% of gross income. Total debt payments should not exceed 36%.

Minimum 3–5% for conventional loans, 3.5% for FHA, 0% for VA/USDA. Aim for 20% to avoid PMI.

Private Mortgage Insurance protects the lender if you default. Required when down payment is under 20%. Avoid by saving a 20% down payment.

Better credit = lower interest rate = lower monthly payment = more buying power. A 2% rate difference on a $300,000 loan saves $350+/month.

Pre-qualification is an estimate based on self-reported information. Pre-approval involves verified documentation and an actual commitment from a lender.

Yes, if your DTI allows. Student loans are included in the back-end ratio (36%). High payments may reduce what you qualify for.

1–2% of the home's value annually. For a $400,000 home: $4,000–$8,000/year or $333–$667/month.