How Much House Can I Afford? A Realistic Guide for First-Time Buyers

You have been pre-approved for $400,000. That does not mean you should spend $400,000. One of the most common and most expensive mistakes first-time buyers make is treating a lender's maximum as a target instead of a ceiling. The amount a bank says you can borrow and the amount you can comfortably afford are almost never the same number.

This guide will walk you through how to figure out what you can actually afford — not just on paper, but in real life. We will cover the formulas lenders use, the hidden costs most buyers underestimate, and the common traps that stretch first-time buyers too thin.

If you want to skip ahead and run your own numbers, try our Affordability Simulator. Otherwise, let's start with the rule most lenders use behind the scenes.

The 28/36 Rule: Where Lenders Start

The 28/36 rule is the most widely used guideline for home affordability, and understanding it gives you an immediate reality check on your budget.

Here is how it works:

• The 28% rule (front-end ratio): Your total monthly housing costs — mortgage principal, interest, property taxes, and homeowner's insurance (often called PITI) — should not exceed 28% of your gross monthly income.
• The 36% rule (back-end ratio): Your total monthly debt payments — housing costs plus all other debts like car loans, student loans, and credit card minimums — should not exceed 36% of your gross monthly income.

Putting It Into Numbers

Let's say you earn $75,000 per year, or $6,250 per month before taxes.

If you already pay $500 per month toward a car loan and student loans, your maximum housing payment under the 36% rule would be $2,250 minus $500, or $1,750 per month. In this case, both rules point to the same number — but that is not always the case.

Keep in mind: these are maximums, not targets. The Consumer Financial Protection Bureau recommends that buyers think carefully about what monthly payment they can sustain over 15 to 30 years — not just what fits today.

Debt-to-Income Ratio: The Number Lenders Watch Closest

Your debt-to-income ratio (DTI) is the back-end number from the 28/36 rule, and it is arguably the single most important metric in your mortgage application. DTI tells a lender how much of every dollar you earn is already committed to debt.

To calculate your DTI, add up all monthly debt obligations — credit card minimums, car payments, student loans, personal loans, child support, and the projected mortgage payment — then divide by your gross monthly income.

A lower DTI does not just help you get approved — it gives you financial breathing room after you move in. Want to see where you stand? Try our Qualification Simulator to run your own numbers.

The Hidden Costs Most First-Time Buyers Underestimate

The mortgage payment is just the beginning. One of the biggest reasons first-time buyers end up house-poor is that they budget for the mortgage but not for everything else that comes with owning a home. Here is what you need to account for beyond principal and interest.

Property Taxes

Property taxes vary dramatically by location. The national average is roughly 1.1% of the home's assessed value per year, but some states and counties charge significantly more. On a $350,000 home, that averages out to about $3,850 per year, or roughly $320 per month added to your housing costs. Check your county assessor's website for the actual rate in the area where you are looking.

Homeowner's Insurance

Lenders require homeowner's insurance, and the cost depends on the home's location, age, condition, and coverage level. The national average is approximately $1,800 to $2,400 per year, but homes in flood zones, hurricane-prone areas, or wildfire regions can cost much more. Get quotes before you finalize your budget.

Private Mortgage Insurance (PMI)

If you put less than 20% down on a conventional loan, your lender will require PMI. This typically costs 0.5% to 1.5% of the original loan amount per year. On a $300,000 loan, that is $1,500 to $4,500 per year — or $125 to $375 per month — added to your payment until you reach 20% equity.

FHA loans have a similar cost called Mortgage Insurance Premium (MIP), which often lasts for the life of the loan unless you refinance into a conventional mortgage.

HOA Fees

If you buy a condo, townhouse, or home in a planned community, you will likely pay monthly HOA dues. These can range from $100 to $500 or more per month depending on the amenities and services included. Lenders factor HOA fees into your DTI calculation, so they directly affect how much house you can afford.

Maintenance and Repairs

This is the cost renters never think about. A general guideline is to budget 1% to 2% of the home's value per year for maintenance and repairs. On a $350,000 home, that is $3,500 to $7,000 per year. Roofs, HVAC systems, water heaters, and appliances all have lifespans, and they do not break on a convenient schedule.

Closing Costs

These are the one-time fees you pay at closing — title insurance, appraisal fees, attorney fees, recording fees, and more. Closing costs typically run 2% to 5% of the purchase price. On a $350,000 home, budget $7,000 to $17,500. Some of these costs can be negotiated or covered by the seller, but you should not assume that will happen. The CFPB's closing cost guide explains each line item.

How Income, Debt, and Credit Score Affect Your Budget

Affordability is not just one number — it is the intersection of several financial factors that work together. Understanding how each one moves your budget up or down helps you make smarter decisions about when to buy and what to aim for.

Income

Your gross monthly income is the foundation of every affordability calculation. Lenders look at stable, documentable income — W-2 wages, salary, and consistent overtime or commissions. If you are self-employed, expect lenders to average your income over the past two years and use the lower figure. Variable income makes qualification harder, so it is especially important to plan conservatively.

Existing Debt

Every dollar of monthly debt directly reduces how much mortgage you can qualify for. A $400 car payment, for example, could reduce your maximum home purchase price by $60,000 to $80,000 depending on the interest rate. If you are carrying significant debt, paying it down before applying for a mortgage can dramatically expand your buying power.

Credit Score

Your credit score does not change how much a lender will let you borrow as dramatically as income or DTI, but it significantly affects the interest rate you are offered. And the interest rate determines your monthly payment.

On a $300,000 loan over 30 years, the difference between a 6.5% and 7.5% rate is approximately $200 per month — or more than $72,000 over the life of the loan. A higher credit score can literally save you tens of thousands of dollars.

For a detailed breakdown of credit score requirements by loan type, read our guide on what credit score you need to buy a house.

Common Affordability Mistakes First-Time Buyers Make

These are the traps we see first-time buyers fall into most often — and every one of them is avoidable.

• Spending up to the pre-approval limit — A pre-approval tells you what a bank will lend you, not what you can comfortably live with. Most financial advisors recommend buying below your maximum.
• Ignoring the total cost of ownership — Your mortgage payment is not your housing cost. Taxes, insurance, PMI, maintenance, and utilities can add 30% to 50% on top of principal and interest.
• Forgetting to budget for closing costs — At 2% to 5% of the purchase price, closing costs can blindside buyers who put every available dollar toward the down payment.
• Not accounting for lifestyle changes — Will you still want to travel, save for retirement, or handle an unexpected expense? A mortgage that leaves no margin is a mortgage that will cause stress.
• Using online calculators without adjusting for local costs — Property taxes, insurance rates, and HOA fees vary widely by location. Generic calculators often underestimate these.
• Buying based on two incomes without a safety net — If your budget requires both earners at full capacity, a job loss or income reduction could put your home at risk. Build in a buffer.

For a complete walkthrough of the buying process and how to avoid common pitfalls, see our first-time homebuyer checklist.

A Realistic Budget Framework

Instead of asking "how much house can I afford," a better question is "what monthly housing cost lets me live the way I want to live?" Here is a framework that goes beyond the lender's formula.

Step 1: Calculate your take-home pay (after taxes, not gross income). This is what you actually have to work with each month.

Step 2: Subtract your non-negotiable monthly expenses — existing debt payments, groceries, transportation, childcare, insurance, and retirement contributions.

Step 3: From what remains, decide how much you want to allocate to housing. Financial planners often suggest keeping total housing costs at or below 25% of your take-home pay — a more conservative target than the 28% gross income rule lenders use.

Step 4: From that housing budget, subtract estimated property taxes, insurance, PMI (if applicable), HOA fees, and a maintenance reserve. What is left is the mortgage payment you can actually afford.

This approach works backward from your real life instead of forward from a lender's formula. It is less exciting than hearing you qualify for $450,000, but it is far more likely to lead to a home you enjoy living in — rather than one that keeps you up at night. The U.S. Department of Housing and Urban Development offers additional budgeting resources for first-time buyers.

Frequently Asked Questions