How Much House Can I Afford?

If you’ve started looking at homes or mortgage rates, you’ve probably asked yourself: how much house can I actually afford? The number you see on listings isn’t always the number that makes sense for your budget, and lenders don’t just look at the price of the home. They look at your income, your existing debt, and how much of your paycheck would go toward housing each month.

There’s no single formula that fits everyone. Some people are comfortable stretching a bit for a home they plan to stay in for decades; others prefer a smaller payment so they can save more or handle surprises. What we can do is walk through how lenders and financial guidelines typically answer “how much house,” and how you can turn that into a number that works for you.

Lenders and financial guidelines often cap how much of your income can go toward housing and toward debt in general. Two ratios show up again and again: front-end DTI and back-end DTI.

Front-end DTI is just your housing payment as a share of your gross monthly income. If you make $6,000 a month before taxes and your housing payment is $1,680, your front-end DTI is 28%. A lot of conventional guidance says to keep that at or below 28%, though some programs allow higher.

Back-end DTI is your housing payment plus all your other monthly debt (car loans, student loans, minimum credit card payments, and so on) divided by that same gross monthly income. So if housing is $1,680 and you have another $500 in debt payments, that’s $2,180 total. On $6,000 income, your back-end DTI is about 36%. Many lenders like to see back-end DTI at or below 36%, but again, it varies by loan type and lender.

Your maximum housing payment is usually limited by both. You can’t go over the front-end cap, and once you add in your other debt, your total can’t go over the back-end cap. So the “room” you have for a house payment depends on how much other debt you’re already carrying.

When we talk about a housing payment in the DTI sense, we’re not just talking about principal and interest on the mortgage. Lenders typically include principal, interest, property taxes, homeowners insurance, and, if you have one, HOA dues. Those are the things you have to pay every month to keep the roof over your head.

That’s why your “max housing payment” from a DTI perspective isn’t all available for the loan itself. Once you subtract what you’ll pay in taxes, insurance, and HOA, whatever is left is what you can put toward principal and interest. That remainder is what drives the loan amount you can afford. From there, with a down payment, you get to a max home price.

If you’re early in the process and don’t know exact tax and insurance numbers yet, that’s normal. You can use rough estimates (for example, a percentage of home value for taxes, or a ballpark for insurance) and refine later. The goal at this stage is a realistic range, not a number to the dollar.

A mortgage affordability calculator does the math in that order: it starts from your income and a DTI limit, subtracts your other monthly debt to see how much is left for housing, then subtracts taxes and insurance and HOA to get a max principal-and-interest payment. From that payment, plus your interest rate and loan term, it backs into a maximum loan amount. Add your down payment and you get an estimated max home price.

It’s a useful way to see how sensitive that number is. Bump your rate up a bit, or add a car payment, or assume higher taxes, and the affordable price drops. Pay off a loan or get a slightly lower rate, and it can go up. You can also play with the DTI percentage to see how strict or relaxed you want to be.

Keep in mind that this is an estimate. Lenders have their own rules, and they may use different DTI limits or add other requirements. But for “how much house can I afford?” in plain language, this is the kind of logic they’re using, and you can use it too to set a comfortable range before you shop. If you want to run the numbers yourself, try our Mortgage Affordability Calculator.