How Much House Can You Afford? The 28/36 Rule Explained

Updated May 31, 2026 · 8 min read

Few financial questions feel as exciting, or as nerve-racking, as "how much house can I afford?" It is tempting to treat the answer as a single number a bank hands you. But the figure a lender will approve and the figure you can comfortably live with are often very different. The amount you qualify for is the ceiling; the amount you should borrow usually sits well below it. This guide covers the classic 28/36 rule, what really counts as debt, the full cost of owning a home, and how to turn all of that into a realistic price range.

Why a Bank's Maximum Is Not Your Budget

A lender's approval is built around the odds that you will keep making payments — not around whether you can still take a vacation, save for retirement, or absorb a surprise car repair. Two households with identical incomes can have very different real budgets depending on their goals, job security, and how much financial breathing room helps them sleep at night. So treat any pre-approval as the top of a range, not a target. The goal is not the largest loan a bank will grant; it is a payment that fits your life with room to spare.

The 28/36 Rule

The 28/36 rule is a long-standing guideline lenders and financial planners use to size a sustainable mortgage. It is really two limits working together, expressed as percentages of your gross monthly income — what you earn before taxes and deductions.

The Front-End Ratio (28 percent)

The front-end ratio looks only at your housing costs. The guideline says your total monthly housing payment should stay at or below 28 percent of gross monthly income. Divide the proposed housing payment by your gross monthly income; if the result is 0.28 or less, you are within the limit. The lower you go, the more cushion you keep for everything else.

The Back-End Ratio (36 percent)

The back-end ratio takes a wider view. It adds all of your recurring monthly debt payments — housing included — and keeps the total at or below 36 percent of gross monthly income. Because it captures your car loan, student loans, and credit-card payments alongside the mortgage, it is often the limit that actually binds: someone with significant debt may hit 36 percent long before reaching the 28 percent housing limit.

Different loan programs flex these numbers, and strong factors like a large down payment or excellent credit can stretch them — but 28/36 remains a sound, conservative starting point.

What Lenders Count as Monthly Debt

For the back-end ratio, lenders tally the recurring obligations on your credit report and in your monthly budget. Typically this includes:

• The proposed monthly housing payment on the home you want
• Auto loan or lease payments
• Student loan payments
• Minimum required credit-card payments (not your full balance)
• Personal loans and other installment-loan payments
• Court-ordered obligations such as child support or alimony, where applicable

Just as important is what usually is not counted: everyday living expenses like groceries, utilities, and gas that are not financing a debt. Those costs are real, which is one more reason to treat the ratios as a ceiling for caution. Paying down a debt before you apply, especially a car loan, can meaningfully raise the housing payment you qualify for.

The Full Cost of "Housing"

When the 28 percent rule refers to your housing payment, it means more than just the loan. Lenders look at the complete monthly cost of keeping the home, often abbreviated as PITI and then some:

• Principal — the portion of each payment that reduces the amount you borrowed.
• Interest — the cost of borrowing, largest in the early years of the loan.
• Property taxes — levied locally and usually collected monthly through an escrow account.
• Homeowners insurance — coverage your lender requires to protect the property.
• PMI (private mortgage insurance) — an added cost that often applies when the down payment is below a conventional threshold, and can typically be removed later as you build equity.
• HOA dues — homeowners-association fees for some condos and planned communities, which can add a meaningful amount.

It is easy to underestimate this true monthly cost. Our mortgage calculator focuses on the principal and interest portion — the part driven by your loan amount, rate, and term. So when you budget against the 28 percent guideline, leave headroom for taxes, insurance, any PMI, and HOA dues on top of the figure the tool shows.

How Down Payment, Rate, and Term Change the Answer

Three levers move what you can afford more than almost anything else, and understanding how each behaves helps you shop with intuition.

• Down payment. A larger down payment shrinks the amount you borrow, lowering your monthly principal and interest. It can also help you clear the threshold where PMI drops away. More cash up front almost always means a smaller monthly cost — though never at the expense of leaving yourself with no emergency savings.
• Interest rate. The rate has an outsized effect because it applies to the whole balance for the life of the loan. When rates are higher, the same monthly budget buys a smaller loan; when they are lower, it stretches further. Even a modest difference can shift your price range, so it pays to compare more than one lender.
• Loan term. A longer term, such as 30 years, spreads the balance over more payments and lowers each one, raising the price you can fit under the 28 percent limit — but you pay interest longer and more of it overall. A shorter term, such as 15 years, raises the monthly payment yet builds equity faster and costs far less in interest. The right choice matches your cash flow and goals.

A Worked Example

The figures below are hypothetical round numbers chosen to show the method, not to reflect any real rate or local cost. Suppose your household earns $6,000 gross per month. Start with the two ratios:

• Front-end (28 percent): 0.28 times $6,000 gives a maximum housing payment of about $1,680 per month. That figure has to cover principal, interest, taxes, insurance, and any PMI or HOA dues — not principal and interest alone.
• Back-end (36 percent): 0.36 times $6,000 gives a maximum of about $2,160 for all debts combined. Imagine you already pay $400 a month toward a car loan and $260 toward student loans — $660 in existing debt. Subtracting that from $2,160 leaves roughly $1,500 for housing.

Because the back-end limit ($1,500) is lower than the front-end limit ($1,680), the back-end ratio governs — the more conservative number wins. So your sustainable total housing payment is about $1,500 per month.

Next, carve out the non-loan parts of that payment. Say you set aside roughly $300 a month for taxes, insurance, and any HOA dues. That leaves about $1,200 for principal and interest. Plug that target into the mortgage calculator, set the rate and term to match what lenders quote you, and read off the loan amount that produces it. Add your planned down payment, and you have a rough purchase-price range. Because rates and local taxes vary, treat it as a starting bracket to refine, not a precise verdict.

Beyond the Formula

The 28/36 rule is a strong filter, but a healthy purchase depends on factors no ratio captures. Before you commit, weigh these too:

• Emergency savings. Aim to keep a cushion of several months of essential expenses after closing. A home brings surprise costs, and a drained account turns a small problem into a crisis.
• Closing costs. Buying a home involves one-time fees on top of the down payment — lender charges, title and escrow, prepaid taxes and insurance. Budget for them so they do not eat into the reserves you meant to keep.
• Job and income stability. A payment that fits today should still fit if your income dips. Variable or commission-based income deserves an extra margin of safety.
• Lifestyle and quality of life. A mortgage at the very top of your range can crowd out travel, hobbies, and the freedom to say yes to things. Buying a little less house often buys a lot more peace of mind.
• Get pre-approved. A lender pre-approval turns estimates into a concrete number, shows sellers you are serious, and surfaces credit issues early — while you still have time to fix them.

Key Takeaways

• The most you can borrow is a ceiling, not a target; build in room to spare.
• The 28/36 rule caps housing at 28 percent of gross monthly income and total debt at 36 percent.
• The back-end ratio often binds first, so paying down debt can expand your budget.
• A true housing payment includes taxes, insurance, PMI, and HOA dues on top of principal and interest.
• Down payment, interest rate, and loan term are the biggest levers on what fits your budget.
• Reserve emergency savings and closing-cost funds, and get pre-approved before you shop in earnest.

Ready to turn these ideas into real numbers? Try the mortgage calculator to see how prices, rates, and terms shape your monthly principal and interest, and use the loan calculator to size up the car or personal loans that count toward your back-end ratio.