How Much House Can I Afford in the U.S.? Understanding DTI and the True Cost of Homeownership

TL;DR: US lenders use the 28/36 debt-to-income rule to determine your maximum mortgage. Your pre-approval number is the ceiling, not your real budget, property taxes, insurance, HOA fees, and your actual lifestyle costs all reduce what you can comfortably afford.

You have been pre-approved. The number on that letter looks big. Maybe bigger than you expected. And now you are staring at Zillow, punching in prices, trying to figure out where reality actually lands.

That number on your pre-approval letter is not what you can afford. It is the maximum a lender is willing to let you borrow based on a formula that does not care about your actual life, your savings goals, your travel plans, your kids' daycare, or the fact that you like eating out more than twice a month. The gap between what a lender says you can borrow and what you can actually handle without feeling house-poor is where most buyers make their biggest mistake.

This is a guide to closing that gap. We will walk through exactly how much mortgage you can afford using the debt-to-income ratio that lenders actually use, how the same math works in Canada, the UK, and Australia, and the hidden costs that can quietly blow up your budget if you are not watching.

The 28/36 Rule: The Benchmark That Drives Every US Mortgage Decision

American mortgage underwriting runs on a pair of ratios known as the 28/36 rule. If you have ever wondered what lenders are actually looking at when they pull your credit and ask for your pay stubs, this is it.

The front-end DTI, also called the housing ratio, caps your total monthly housing costs at 28% of your gross monthly income. Everything counts here: principal and interest on the loan, property taxes, homeowners insurance, private mortgage insurance if you are putting less than 20% down, and HOA fees if you are buying in a community that charges them. That 28% is the lender's way of making sure you are not spending so much on shelter that you cannot cover the rest of your life.

The back-end DTI takes a wider view. It includes all your recurring debt payments, the housing costs above plus car loans, student loans, minimum credit card payments, personal loans, and any court-ordered payments like child support. This ratio caps at 36% for most conventional loans. It is the more restrictive of the two for most borrowers, especially anyone carrying student loans or car payments.

Front end DTI vs back end DTI, the distinction matters because they frequently tell different stories. You might have a comfortable front-end ratio and a blown-out back-end ratio if you are carrying heavy car or student loan debt. The conservative one is the one that matters.

Here is how those ratios translate into real numbers:

If you have been googling "how much mortgage can I get with 100k salary," the short answer is that lenders will cap your housing payment around $2,333 on the front end, but your actual limit may be lower depending on what other debts you carry.

Conventional vs FHA: DTI Limits Are Not the Same

A lot of first-time buyers assume the 28/36 rule is universal. It is not. That standard applies to conventional loans backed by Fannie Mae and Freddie Mac. If you are going the FHA route, the limits are looser.

FHA allows a front-end DTI up to 31% (and sometimes 40% with compensating factors like a strong credit score or significant cash reserves). The back-end can stretch to 43%, even 50% in some cases. This is why first-time buyers with student loans often gravitate toward FHA, the conventional loan DTI limits 2026 may feel too tight if you have significant existing debt.

The trade-off is that FHA charges mortgage insurance premium (MIP) for the life of the loan unless you put at least 10% down. Conventional loans drop PMI once you reach 20% equity. So the question becomes whether you want the higher DTI flexibility of FHA or the lower long-term cost of conventional.

The fha dti limits 2026 and conventional loan dti limits 2026 are both worth checking before you settle on a loan program. A good lender can run your scenario through both and show you which one pencils out better.

How Much Home Can You Actually Afford? A Real Example

Let us make this concrete. Say you earn $100,000 a year. Your gross monthly income is $8,333. You have a car payment of $400 and student loans of $300, totaling $700 in monthly debt.

Front-end limit: $8,333 × 28% = $2,333 for total housing

Back-end limit: ($8,333 × 36%) − $700 = $2,300 for total housing

Your binding limit is $2,300. That is what you can put toward principal, interest, taxes, insurance, and HOA. Now strip out the non-mortgage pieces:

• Property taxes: $300/month
• Homeowners insurance: $120/month
• PMI (if putting less than 20% down): $150/month

That leaves about $1,730 for principal and interest. At a 6.5% rate on a 30-year fixed loan, that works out to roughly $275,000 in loan amount. With a 10% down payment, you are looking at a home price around $305,000.

That is very different from the $400,000+ number your pre-approval letter might show. And that is the point. A home affordability calculator FHA might give you slightly more room because of the higher DTI limits, but the principle is the same: the real number is lower than the maximum.

The Hidden Costs of Buying a House That Change the Math

Too many buyers focus entirely on the mortgage payment and discover too late that owning a home costs significantly more than they planned. The hidden costs of buying a house fall into two categories: recurring costs that eat into your monthly cash flow and one-time costs that drain your savings at closing.

Property Taxes: The Cost That Follows You Forever

Property taxes are not optional. They are baked into your monthly payment via an escrow account that your lender manages. And they vary wildly depending on where you live.

If you are shopping across state lines or even across counties within the same state, using a property tax calculator by state 2026 before you make an offer can save you from a nasty surprise. A $400,000 home in Texas might carry $7,000 a year in property taxes. The same-priced home in Colorado might cost $2,500. That difference is nearly $400 a month, enough to change what you can afford entirely.

Homeowners Insurance: The Average Cost Is Climbing

The average homeowners insurance cost 2026 has been rising, driven by climate-related claims in states like Florida, California, and Texas. Expect to pay somewhere between $1,200 and $2,500 annually depending on where you live and the replacement cost of the home. If you are buying in a flood zone, budget another $700 to $1,000 per year for flood insurance on top of that.

Escrow Shortages: The Surprise Payment Bump

Here is something lenders rarely warn you about upfront. When your property taxes or insurance premiums go up, and they will, your lender recalculates your escrow payment to cover the difference. If the increase is larger than expected, you can end up with what is called an escrow shortage.

An escrow shortage calculator can help you estimate how much your payment might jump when taxes and insurance rise. This is not a one-time thing either. You should expect your escrow payment to drift upward over time. If you are buying near the top of your DTI limit, even a $100 increase in your monthly escrow payment can squeeze your budget.

Closing Costs: The Cash You Need Before You Move In

This is the one that catches buyers off guard the most. Closing costs calculator usa tools exist because so many people focus on the down payment and forget that closing costs add 2% to 5% to the cash they need at the table. On a $350,000 home, that is $7,000 to $17,500 in addition to your down payment.

Closing costs include the lender's origination fee, the appraisal, the title search and insurance, credit report fees, recording fees, prepaid interest, and escrow deposits for taxes and insurance. Some of these are fixed costs. Others scale with the purchase price. Either way, if you are emptying your savings for the down payment and forgetting about closing costs, you are setting yourself up for a cash crunch before you even get the keys.

How DTI Affordability Works Outside the US

The beauty of the debt-to-income framework is that the concept translates everywhere, even if the specific ratios and rules change.

Canada

Canadian lenders use a Gross Debt Service (GDS) ratio and a Total Debt Service (TDS) ratio that mirror the front-end and back-end DTI framework. The GDS limit is typically 32% for conventional mortgages and 39% for insured mortgages (where you put less than 20% down). The TDS limit is 40% for conventional and 44% for insured.

Canada's unique twist is the mortgage stress test. Even if your DTI qualifies you for a certain loan amount, you must prove you can afford payments at a rate that is roughly 2% higher than your contract rate, or the Bank of Canada's five-year benchmark rate, whichever is higher. This stress test was introduced to prevent borrowers from overextending when rates are low, and it has significantly reduced the maximum purchase price for many Canadian buyers.

Property taxes in Canada are generally lower than in the US, averaging 0.5% to 1.0% of assessed value depending on the province. But CMHC insurance premiums are higher than US PMI, adding 2.8% to 4.0% of the loan amount for down payments under 10%.

United Kingdom

UK affordability works differently. Lenders use an income multiple rather than a strict DTI ratio. The standard is 4 to 4.5 times your annual income, though some lenders will go to 5 or even 5.5 times for high-income borrowers or those in stable professions like medicine or law.

For a dual-income household earning £80,000 combined, that means a maximum mortgage of £320,000 to £360,000. But the lender will still stress-test your application, typically at a rate of 6% to 7%, to make sure you can handle rate increases.

The UK does not have property taxes in the same sense as the US. Instead, buyers pay Stamp Duty Land Tax at closing, a progressive tax starting at 0% on the first £250,000 (for first-time buyers) and rising to 5%, 10%, and 12% on higher brackets. Monthly costs include council tax, which runs roughly £1,200 to £2,500 per year depending on the property band and location.

Australia

Australian lenders use a DTI assessment similar to the US but with their own flavor. The typical maximum is a 28% to 32% front-end ratio and a 36% to 40% back-end ratio depending on the lender and whether you are an owner-occupier or an investor.

The Australian twist is that lenders apply a "buffer rate", typically 3% above your actual rate, to stress-test your ability to repay. With variable rates around 6% to 6.5%, that means being assessed at 9% or higher.

Stamp duty in Australia is state-based and expensive. On a $700,000 home in New South Wales, stamp duty runs around $28,000 for non-first-home buyers. First-home buyers get substantial exemptions or concessions depending on the state.

How to Find Your Real Number

The most reliable way to determine how much house you can afford is to use a how much house can I afford calculator that accounts for all of these variables simultaneously, not just income and debt, but taxes, insurance, PMI, HOA fees, and the specific DTI limits of your loan program.

A solid 28 36 rule mortgage calculator will show you both your front-end and back-end limits, tell you which one is binding, and work backward to a maximum home price. The US Affordability Tool does exactly this. Run your numbers through it with different down payment amounts and interest rates to see how each variable moves the needle.

For buyers considering FHA, a dedicated home affordability calculator FHA is worth using separately because the DTI limits are different enough that it can change your target price by $30,000 or more.

Common Mistakes That Trip Up Buyers

Buying at the pre-approval limit. Lenders have no incentive to tell you to spend less. Your pre-approval shows the ceiling. Treat the ceiling as a warning sign, not a target.

Ignoring the escrow cushion. When your property tax assessment increases or your insurance premium goes up, and both will, your escrow payment rises with them. Budget a 10% to 15% buffer above your initial escrow estimate.

Forgetting that closing costs are real money. If you are putting 5% down, you need closer to 7% to 9% of the purchase price in cash by the time you factor in closing costs and prepaids.

Using the same DTI for every loan type. The conventional loan DTI limits 2026 are tighter than FHA. Run both scenarios before you decide.

The Bottom Line

How much house you can afford comes down to the debt to income ratio for mortgage that your lender uses, plus the hidden costs that your lender does not emphasize. The 28/36 rule is the starting point. Property taxes, insurance, PMI, HOA fees, closing costs, and maintenance are the real deciders.

Run your numbers through a calculator that accounts for all of it. Talk to a lender who will walk you through both conventional and FHA options. And leave yourself room, financial and psychological, to live your life beyond your mortgage payment.

The right house is the one that feels good when you wake up in it, not the one that makes you check your bank account every morning.

Frequently Asked Questions

This article is for educational and informational purposes only and does not constitute financial, legal, or mortgage advice. Debt-to-income ratio guidelines, interest rates, and loan program specifications are subject to change and vary by lender. Always consult a licensed mortgage professional for guidance specific to your situation. All affordability calculations are estimates and should be verified with a formal pre-approval from a licensed lender.