How Much House Can I Afford on My Income?

“How much house can I afford?” feels like it should have a clean answer — some multiple of your salary you could recite at a dinner party. It does not. The real answer is a ceiling, and it is set less by what you earn than by what you already owe and what a lender will charge you to borrow.

This guide walks through how that ceiling is calculated, why two people with identical salaries can afford very different homes, and how to find the number that actually fits your life — not just the one a lender will approve.

Income is the starting point, not the answer

The old rule of thumb was “buy a house worth two or three times your salary.” It is a fine bar-napkin estimate, but it quietly ignores the two things that move the number most: your other debts and the interest rate.

Consider two people who both earn $90,000 a year. One has no car payment, no student loans, and a clean slate. The other carries $700 a month in car and student-loan payments. At the same salary, the same down payment, and the same mortgage rate, the second person can afford a meaningfully smaller home — because a chunk of their income is already committed before the mortgage is even in the picture.

That is why a lender never looks at income alone. Income tells them the size of the pie. Your debts tell them how much of it is already spoken for.

How lenders actually draw the line

Lenders cap your borrowing using your debt-to-income ratio (DTI) — the share of your gross monthly income that goes toward debt payments. There are two versions, and both matter:

• Front-end DTI counts only your future housing payment against your income. A common target is around 28%.
• Back-end DTI adds every other monthly debt — car loans, student loans, credit-card minimums — on top of the housing payment. Many conventional loans cap this around 36%, though some programs stretch to 43% or beyond.

The pairing of these two — often written as the 28/36 rule — is the backbone of the whole affordability calculation. Your income sets the pool; the ratios decide how much of it a lender will let you spend on a house. We break down what DTI is and why it caps your budget in its own guide.

Working the math backward

Here is the sequence, using illustrative numbers to show the shape of it. These are examples, not current rates.

Say you earn $90,000 a year — $7,500 a month gross. With a target back-end DTI of 36%, your total debt payments can run up to $2,700 a month. Now subtract what you already owe:

That $2,200 is not all mortgage. It has to cover the whole housing payment — principal, interest, property taxes, and homeowners insurance, plus any HOA dues. Lenders call that bundle PITI. Once you carve out, say, $400 a month for taxes and insurance, only about $1,800 is left for principal and interest.

From there it is arithmetic. A given monthly principal-and-interest payment supports a specific loan size at a specific rate — and the rate matters enormously. At a low rate, $1,800 a month buys a large loan; at a high rate, the same payment buys a much smaller one. Add your down payment to the loan the payment supports, and you have your maximum home price.

You do not have to run that loop by hand. The Home Affordability Calculator does exactly this — takes your income, debts, down payment, rate, and target DTI, and solves backward to your max home price with the full payment breakdown behind it.

Why the rate changes everything

Two buyers with the same income, debts, and down payment can afford very different homes purely because of the interest rate they lock. A monthly payment is fixed by your budget, but the loan that payment supports shrinks as rates rise. When rates climb, affordability falls even if your paycheck never changes — which is why the same salary buys less house in a high-rate year than in a low-rate one.

This is also why your down payment does double duty. It lowers the loan you need, and a larger one can help you clear the 20% threshold that removes private mortgage insurance from the monthly bill — freeing up more of your PITI budget for the loan itself.

The number you can afford vs. the number you should spend

Here is the part most calculators skip. The maximum a lender approves is a ceiling, not a target. It is the most the DTI math allows — not the amount that leaves you comfortable.

The approved number does not account for retirement savings, an emergency fund, home maintenance (roofs and water heaters do not care about your DTI), childcare, or the simple margin that keeps a surprise expense from turning into a crisis. Plenty of buyers deliberately shop below their max for exactly this reason. A home that fits your DTI can still not fit your life.

A good practice: find your ceiling, then ask what monthly payment you would actually be content writing a check for every month for the next thirty years. That second number is usually lower — and it is the one worth buying to.

Frequently asked questions

How much house can I afford on my income?

There is no single multiple of salary that answers it. Your maximum home price depends on your income, your existing monthly debts, your down payment, the interest rate, and your target debt-to-income ratio. Lenders typically cap your total debt payments — housing plus everything else — around 36% of gross monthly income, then work backward from that ceiling to a loan amount and a home price. Two people with the same salary can afford very different homes depending on their debts and their rate.

What percentage of my income should go to a mortgage?

A common guideline is that your housing payment alone stays under about 28% of gross monthly income (front-end DTI), and your total debt payments under about 36% (back-end DTI). These are guidelines, not laws — some loan programs allow higher ratios — but staying near or below them leaves room for savings, maintenance, and the unexpected.

Should I buy at the top of what I’m approved for?

Usually not. The approved maximum is what the debt-to-income math permits, not what leaves you financially comfortable. It ignores maintenance, utilities, retirement savings, and emergency funds. Many buyers intentionally shop below their max so a surprise expense or income dip does not strain the budget.

Not financial advice. The figures above are illustrative examples, not current mortgage rates, tax figures, or lending limits. Actual affordability depends on your credit, the loan program, and a lender's full underwriting. Confirm real numbers with a licensed lender before deciding.