How Much House Can I Afford: Income, Debt, and Down Payment

Figuring out how much house you can afford comes down to three numbers: your income, your debt, and your down payment. Lenders look at all three to decide what size loan to approve, but the amount a lender approves is not always the amount that fits comfortably into your life. This guide walks through the standard rules of thumb, shows how to run the math yourself, and covers the costs that surprise many buyers.

Why These Three Numbers Matter

A mortgage payment is a monthly obligation, usually for 15 or 30 years. Lenders want confidence that you can keep paying it. They check how much money comes in (income), how much already goes out (debt), and how much of your own cash you can put toward the purchase (down payment). Understanding each piece lets you set a realistic price range before you fall in love with a listing you cannot comfortably afford.

The 28/36 Rule: A Common Starting Point

Many lenders use a guideline called the 28/36 rule, sometimes with adjustments. It works like this:

• Front-end ratio: Your total housing costs should stay at or below 28% of your gross monthly income.
• Back-end ratio: Your housing costs plus all other monthly debt payments should stay at or below 36% of your gross monthly income.

Gross income means your pay before taxes and deductions. Some loan programs allow back-end ratios as high as 43% or even 50%, but a higher ratio usually means a tighter monthly budget and more risk if your income changes.

Step 1: Start With Your Income

Add up your gross monthly income from all stable sources. If you are paid hourly, use a realistic average rather than your best week. If you receive bonuses, overtime, or commissions, lenders often average the last two years of earnings instead of counting a single strong month.

A simple example: if you earn $6,000 per month before taxes, 28% of that is $1,680. That figure becomes your starting ceiling for housing costs.

Step 2: Add Up Your Monthly Debts

Next, list the minimum payments you owe each month. Include:

• Car loans and lease payments
• Student loans
• Credit card minimum payments
• Personal or installment loans
• Court-ordered payments such as child support

Do not include everyday expenses like groceries, utilities, or streaming subscriptions. Lenders focus on debts that appear on your credit report and require a fixed monthly payment.

Using the same $6,000 income: if your monthly debt payments total $500, subtract that from 36% of your income ($2,160). You are left with about $1,660 for housing. Since that is lower than the $1,680 front-end figure, the debt limit becomes your real ceiling.

Step 3: Understand Your Down Payment

Your down payment is the cash you pay upfront, which reduces the amount you borrow. It affects your budget in three ways:

• Smaller loan: A larger down payment lowers your monthly principal and interest.
• Fewer added costs: Putting down 20% or more typically avoids private mortgage insurance, an extra monthly charge added when the down payment is small.
• Better terms: A stronger down payment can open the door to more loan options and competitive rates.

Many buyers put down far less than 20%. Some loan programs allow 3% to 5% down, and certain government-backed loans allow even less. The trade-off is a higher monthly payment and often mortgage insurance until you build enough equity.

One important caution: do not empty your savings for a down payment. Keep an emergency fund of at least three to six months of living expenses, because home repairs and unexpected bills arrive without warning.

Step 4: Include the Costs Beyond the Mortgage

Your monthly payment usually contains more than the loan itself. Budget for:

• Property taxes: Collected monthly through an escrow account in many cases.
• Homeowners insurance: Required by nearly every lender.
• Private mortgage insurance: Applies when your down payment is below roughly 20%.
• Homeowners association fees: Common with condos and some planned neighborhoods.
• Maintenance and repairs: A common rule of thumb is to set aside 1% of the home’s value each year.

You also need upfront cash for closing costs, which typically run 2% to 6% of the purchase price, covering fees such as appraisal, title, and loan origination.

Step 5: Turn Your Payment Into a Price

Once you know your comfortable monthly housing figure, subtract estimated taxes, insurance, and any association fees. What remains is roughly what you can spend on principal and interest.

From there, a mortgage calculator converts the payment into a loan amount. As a rough reference, at a 7% interest rate on a 30-year fixed loan, the principal and interest payment is about $665 per month for every $100,000 borrowed. If your remaining budget were $1,310 per month, that would support a loan near $197,000. Adding a 20% down payment brings the estimated home price to roughly $246,000.

Rates change constantly, so always run your own numbers with a current calculator rather than relying on a rule of thumb alone.

Step 6: Get Pre-Approved

A pre-approval is a lender’s written estimate of how much it will lend you, based on verified income, debts, and credit. It gives you a concrete number to shop with and shows sellers you are a serious buyer. Pre-approval is not a guarantee of a final loan, but it is the closest early signal of your true range.

What Lenders Approve vs. What You Can Comfortably Pay

A common mistake is treating the maximum approval as a target. Lenders calculate what you can technically repay, not what leaves room for savings, travel, childcare, or a career change. Consider aiming below your maximum so that a raise or a surprise expense does not turn your mortgage into a strain.

Signs You May Be Stretching Too Far

• Your housing payment would exceed 30% of your take-home pay.
• You would have little or no emergency savings after closing.
• You are counting on future raises to make the payment work.
• You would need to cut retirement contributions to stay afloat.

If any of these apply, consider a lower price range or waiting until your down payment or income grows.

Frequently Asked Questions

What percentage of my income should go to a mortgage?

A common guideline is to keep total housing costs at or below 28% of gross monthly income, with all debt payments staying under 36%. Some lenders allow more, but a lower percentage offers more breathing room.

Does a bigger down payment lower my monthly payment?

Yes. Borrowing less reduces principal and interest, and reaching a 20% down payment usually removes the private mortgage insurance charge as well.

How much cash should I have beyond the down payment?

Plan for closing costs of roughly 2% to 6% of the purchase price, plus an emergency fund covering three to six months of expenses, plus a small buffer for moving and immediate repairs.

The Bottom Line

To estimate how much house you can afford, calculate 28% of your gross monthly income for housing, check that housing plus your existing debts stays under 36%, and factor in your down payment along with taxes, insurance, and maintenance. Then confirm the number with a pre-approval and choose a price below your maximum so your budget stays comfortable. If you found this helpful, explore more practical guides on budgeting, home buying steps, and managing debt to keep your finances on track.