How to Figure Out How Much House You Can Really Afford

A lender's pre-approval tells you the maximum they'll risk on you — not the amount you can comfortably live with. Those are very different numbers. Here's how to find the one that lets you sleep at night.

Buying a home is the largest purchase most people ever make, and the price tag is only the beginning. Get the number right and your home becomes a foundation for the rest of your financial life. Get it wrong — stretch too far — and you become "house poor," technically a homeowner but with no money left for anything else. The good news is that working out a genuinely affordable price isn't guesswork. It follows a handful of well-established rules that lenders and financial planners have used for decades.

Start with the 28/36 rule

The most enduring guideline in home buying is the 28/36 rule, and it's the backbone of how lenders think about risk.

• The 28% front-end ratio: Your total monthly housing payment shouldn't exceed 28% of your gross (pre-tax) monthly income. "Housing payment" here means principal, interest, property taxes and insurance — often abbreviated PITI.
• The 36% back-end ratio: Your total monthly debt payments — housing plus car loans, student loans, credit card minimums and everything else — shouldn't exceed 36% of gross monthly income.

So if you earn $6,000 a month before tax, the 28% rule caps your housing payment around $1,680, and the 36% rule caps your total debt around $2,160. Whichever limit you hit first is your ceiling. Our House Affordability Calculator applies both rules at once and works backward to a maximum home price, factoring in your income, existing debts, down payment and interest rate.

The 28/36 rule isn't a law — it's a guardrail. Plenty of lenders will approve you for more. The rule exists to protect you from them.

Know your debt-to-income ratio

That back-end ratio has a name lenders live by: debt-to-income, or DTI. It's simply your total monthly debt payments divided by your gross monthly income, expressed as a percentage. Most mortgage programs want to see a DTI below 43%, and the best rates go to borrowers under 36%. Before you even shop for a home, it's worth checking yours with our Debt-to-Income Calculator. If it's high, paying down a car loan or credit card before applying can meaningfully increase how much home you qualify for — and lower your rate.

The real monthly cost of a home

Here's where many first-time buyers get caught out. The mortgage payment you see quoted is usually just principal and interest. The true monthly cost of owning includes several more line items:

• Property taxes — vary widely by location, often 0.5% to 2%+ of the home's value per year.
• Homeowners insurance — required by lenders, and rising in many regions.
• Private mortgage insurance (PMI) — typically required if your down payment is under 20%.
• HOA fees — for condos and many communities, sometimes hundreds a month.
• Maintenance — a common rule of thumb is to budget 1% of the home's value per year for upkeep.

Add these up and the "real" payment can be 25–40% higher than the principal-and-interest figure alone. A thorough Mortgage Calculator lets you include taxes and insurance so you're budgeting for the whole cost, not just the headline number.

How the down payment changes everything

Your down payment does three jobs at once: it lowers the amount you borrow, it can eliminate PMI, and it signals lower risk to lenders (which can earn you a better rate). The classic target is 20% of the purchase price, which is the threshold that typically removes the need for mortgage insurance.

That said, 20% isn't mandatory. Many buyers put down less — some programs allow as little as 3–5% — and simply pay PMI until they build enough equity. The trade-off is a larger loan, a higher monthly payment, and that extra insurance cost. Use our Down Payment Calculator to see how different down payments change your loan amount and whether PMI kicks in.

Why interest rates matter so much

On a 30-year mortgage, the interest rate has an outsized effect on both your monthly payment and the total you'll pay over the life of the loan. Consider a $300,000 loan: at 5% the monthly principal and interest is about $1,610, but at 7% it jumps to roughly $1,996 — nearly $400 more every month, and well over $130,000 more across 30 years. The same house, the same buyer, a wildly different cost, all because of the rate.

This is why it pays to shop lenders, improve your credit score before applying, and understand the difference between the interest rate and the APR (which includes fees). If rates fall significantly after you buy, refinancing can lower your payment — our Refinance Calculator shows whether the savings outweigh the closing costs.

The upfront costs beyond the down payment

Many first-time buyers save diligently for a down payment and then get blindsided at closing. Buying a home carries a stack of one-time costs on top of the deposit, and budgeting for them prevents a nasty surprise. Closing costs — lender fees, appraisal, title insurance, legal fees and taxes — commonly run 2–5% of the loan amount. On a $300,000 mortgage that's $6,000 to $15,000, due at signing. Then come moving expenses, immediate repairs and furnishing, and the reserves lenders often want to see (a few months of payments sitting in your account). A sensible rule is to have your down payment plus another 3–5% of the purchase price set aside before you start seriously shopping. Arriving at closing with a comfortable cushion, rather than scraping the bottom of your savings, is the difference between an exciting milestone and a stressful one.

Renting isn't throwing money away

You'll often hear that renting is "throwing money away" while buying "builds equity." The truth is more nuanced. Buying carries large costs that build no equity at all — mortgage interest (especially in the early years), property taxes, insurance, maintenance and closing fees are all money that simply leaves your pocket, just like rent. In the first several years of a mortgage, the interest portion alone can rival what you'd have paid to rent. Buying tends to win financially when you stay put long enough to spread those upfront costs over many years and let equity and appreciation accumulate — often five years or more. If your job, city or life situation might change sooner, renting can genuinely be the smarter money move, not a failure. Our Rent vs Buy Calculator compares the real multi-year cost of each so you can decide with numbers rather than slogans. The goal isn't to own at any cost; it's to make the housing choice that best fits your finances and your life.

Setting a number you'll be happy with

The affordability formulas give you a ceiling; wisdom is buying below it. Leave room in your budget for retirement savings, an emergency fund, travel, and the ordinary joys that make a house worth living in. A useful gut check: after your full housing payment and all other bills, are you still able to save meaningfully every month? If the honest answer is no, the house is too expensive, no matter what the pre-approval letter says. Run the numbers, add a comfort margin, and buy the home that fits your life — not the one that consumes it.

How lenders actually decide what to approve

Understanding a lender's perspective helps you prepare a stronger application and often qualify for a better rate. Behind the scenes, mortgage approval rests on a handful of factors they weigh together. Your credit score is central — it summarizes how reliably you've repaid debt, and a higher score signals lower risk, which translates directly into a lower interest rate and sometimes a bigger loan. Even a modest improvement in your score before applying can save you thousands over the life of the mortgage, so paying down balances and correcting any errors on your credit report is time well spent.

Next, lenders scrutinize your debt-to-income ratio, because it shows how much room your income has to absorb a new payment. They also want stable, verifiable income — steady employment history reassures them the payments will keep coming — and they check your savings and reserves to confirm you can cover the down payment, closing costs, and a cushion for emergencies. Finally, the loan-to-value ratio (the loan size relative to the home's value) matters: a bigger down payment means a lower ratio, less risk for the lender, and better terms for you.

Here's the crucial mindset shift: a lender's job is to assess the maximum they can profitably lend, factoring in your ability to repay — not the amount that leaves you comfortable. Their approval is a ceiling built around their risk, not your quality of life. A pre-approval letter is a useful shopping tool and a signal to sellers that you're serious, but treat the number on it as the absolute top of a range you'll deliberately buy below. The borrowers who thrive are the ones who qualify for a lot and then choose to spend less, leaving room to live, save and weather surprises. The house that fits your budget with breathing room will always feel better than the one that technically fit the bank's formula.

Frequently asked questions

How much house can I afford on my salary?

A common starting point is 2.5 to 4 times your annual gross income, but the more precise method is the 28/36 rule applied to your monthly income, debts, down payment and interest rate. An affordability calculator gives you a personalized maximum.

What is the 28/36 rule?

It's a lending guideline: keep your monthly housing payment at or below 28% of gross monthly income, and your total monthly debt at or below 36%.

Do I really need a 20% down payment?

No. Many loans allow far less, but putting down under 20% usually means paying private mortgage insurance until you build enough equity, plus a larger loan and higher payment.

What's included in a monthly mortgage payment?

Typically principal, interest, property taxes and homeowners insurance (PITI), and often PMI and HOA fees. Budget for maintenance separately.

How does my credit score affect affordability?

A higher score usually earns a lower interest rate, which lowers your monthly payment — effectively letting you afford more home for the same money.

Should I buy at the top of my budget?

Usually not. Buying below your maximum leaves room for savings, emergencies and life, and protects you from becoming house poor.

What credit score do I need to buy a house?

Requirements vary by loan type and country, but a higher score always helps — it can be the difference between qualifying or not, and between a high and low interest rate. Even a modest improvement before you apply can save you thousands over the life of the loan, so it's worth checking and improving your score first.

How much should I save before buying a home?

Plan for your down payment plus roughly another 3–5% of the price for closing costs, plus moving expenses and a cushion for early repairs and reserves. Arriving with a comfortable margin rather than an empty account makes the whole process far less stressful.

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