How Much House Can You Actually Afford?

“How much house can I afford?” sounds like a simple question. It isn’t, mostly because there are two different answers, and lenders only tell you one of them. There’s the amount a bank will approve you for, and there’s the amount you can actually afford without your budget feeling like a hostage situation every month. Those numbers are often very different — and the gap between them is where a lot of first-time buyers get into trouble.

The bank’s number vs. your number

When a lender pre-approves you, they’re answering one question: “What’s the most this person could pay before we consider them a risky bet?” That’s it. They’re not asking whether you’ll still be able to afford groceries, save for retirement, or handle a surprise car repair. Banks approve based on the edge of what’s mathematically survivable, not the middle of what’s comfortable.

That’s not a knock on lenders — it’s just not their job to protect your lifestyle. That job is yours. So before you start touring homes at the top of your pre-approval letter, it’s worth running your own, more honest number.

The 28/36 rule

The 28/36 rule is a decades-old rule of thumb that most lenders still use as a starting point, and it’s a genuinely useful gut check for you too.

• 28% — the front-end ratio. Your total monthly housing payment — principal, interest, property taxes, homeowners insurance, and any HOA dues — shouldn’t exceed 28% of your gross monthly income.
• 36% — the back-end ratio. All your monthly debt combined (housing plus car loans, student loans, credit cards, and any other minimum payments) shouldn’t exceed 36% of your gross monthly income.

Some lenders will stretch these numbers higher, especially for borrowers with strong credit or low other debt — it’s not unusual to see approvals up to 43% or even higher on the back end. That’s exactly the gap we’re talking about: “will approve” creeps a lot higher than “should spend.”

A worked example

Say your household brings in $85,000 a year, gross. That’s about $7,083 a month.

Rule	Percentage	Monthly amount
Front-end (housing only)	28%	~$1,983
Back-end (all debt)	36%	~$2,550

If you already have $350/month in other debt payments (a car loan, say, and a student loan), that comes out of your back-end number first: $2,550 − $350 = $2,200 available for housing under the back-end rule. Since that’s higher than the front-end limit of $1,983, the front-end number is your binding constraint here — $1,983/month is roughly where your “comfortable” ceiling should sit, before you even talk to a bank.

Why the comfortable number matters more than the max number

A monthly housing payment isn’t just principal and interest. It’s taxes, insurance, maintenance (budget roughly 1% of the home’s value per year for upkeep), utilities that are often higher in a house than an apartment, and the occasional “the water heater died” afternoon. Buyers who stretch to the bank’s maximum number often find there’s nothing left over for any of that — which turns homeownership from a milestone into a monthly source of dread.

Living a little under your max gives you breathing room: an emergency fund that can actually absorb emergencies, room to keep saving for retirement, and the ability to enjoy the home you just spent a small fortune on.

Costs first-timers routinely forget to budget for

The 28/36 rule generally covers principal, interest, taxes, and insurance — but a few other recurring costs tend to catch first-time buyers off guard because they’re easy to overlook until you’re already living in the house:

• Private mortgage insurance (PMI). If your down payment is under 20% on a conventional loan, PMI gets added to your monthly payment until you reach enough equity — often an extra 0.5-1.5% of the loan amount per year.
• HOA dues. Condos and many planned communities charge monthly or annual dues, sometimes hundreds of dollars a month, on top of your mortgage payment. Always ask for the HOA fee before you fall in love with a listing.
• Maintenance and repairs. A commonly cited rule of thumb is budgeting roughly 1% of your home’s value per year for upkeep — some years will be far cheaper, some (a new roof, a failed HVAC system) considerably more.
• Higher utility bills. Detached homes are often noticeably more expensive to heat, cool, and maintain than an apartment of similar size.

None of these show up in a lender’s approval letter, which is exactly why the “comfortable” number in the 28/36 rule matters more than the bank-max number — it’s the number more likely to survive contact with all of these extra, easy-to-forget costs.

Run your own numbers

This math is exactly what powers our affordability calculator — plug in your income, debts, and down payment, and it’ll show you a comfortable, stretch, and bank-max price range side by side, along with a rough monthly payment breakdown.

The rate used in the calculator (7.0% by default) is an illustrative placeholder — mortgage rates move, so check today’s rate with a lender before treating any number here as final.

Your credit score affects more than approval

It’s worth mentioning that your credit score doesn’t just determine whether you get approved — it heavily influences what rate you get, which changes your comfortable-vs-bank-max numbers more than people expect. A borrower with excellent credit can sometimes get a meaningfully lower rate than a borrower with fair credit on the exact same loan, which can shift your affordable price range by tens of thousands of dollars. If your score has room to improve, spending a few months paying down revolving debt and fixing any credit report errors before you apply can be one of the highest-leverage things you do in this entire process.

The honest takeaway

Nobody at the bank is going to stop you from borrowing the maximum they’ll offer. That responsibility sits with you. Use the 28/36 rule as your starting point, adjust down if you have other financial goals you care about (travel, kids, retiring before age 90), and treat your pre-approval letter as a ceiling to stay under, not a target to hit.