How Much House Can You Afford
Before you start browsing listings, you need a clear picture of what you can realistically afford. Stretching beyond your means leads to financial stress and increases the risk of default. This guide explains the key rules and ratios that lenders and financial advisors use to determine a comfortable home purchase range. Model your own scenarios with the Mortgage Payment Calculator.
The 28/36 Rule
The 28/36 rule is a widely used guideline in mortgage lending. It states that your total monthly housing costs, including principal, interest, taxes, insurance, and HOA fees, should not exceed 28 percent of your gross monthly income. Additionally, your total debt payments, housing plus all other debts like car loans, student loans, and credit cards, should stay below 36 percent of gross income.
For example, if your gross monthly income is 6,000, the 28 percent limit means your housing payment should be no more than 1,680. And your total debt payments should stay under 2,160 at the 36 percent threshold. These limits help ensure you have enough remaining income for savings, emergencies, and everyday expenses.
Debt-to-Income Ratio
Lenders evaluate your debt-to-income ratio, or DTI, as a key part of the approval process. DTI is calculated by dividing your total monthly debt obligations by your gross monthly income. Most conventional mortgage programs prefer a back-end DTI of 36 percent or lower, though some programs allow up to 43 or even 50 percent with compensating factors like a large down payment or excellent credit score.
A lower DTI not only improves your approval odds but often qualifies you for a better interest rate. Even a small rate improvement can save thousands over the life of the loan, as explained in our guide to mortgage down payments.
How Down Payment Affects Affordability
The down payment directly impacts both the loan amount and the monthly payment. A larger down payment means you borrow less, which reduces your monthly obligation and total interest. It can also eliminate the need for private mortgage insurance, or PMI, which lenders typically require when the down payment is below 20 percent of the home price.
Common down payment levels are 3.5 percent for FHA loans, 10 percent for moderate conventional loans, and 20 percent for the benchmark that avoids PMI. On a 300,000 home, the difference between 10 percent down and 20 percent down is 30,000 in loan amount, which translates into significantly lower payments and interest over the full mortgage term.
Practical Takeaway
Start by calculating 28 percent of your gross monthly income to set a housing payment ceiling. Then subtract any existing debt payments from the 36 percent limit to see how much room you have. Factor in property taxes, insurance, and HOA fees, which can add 400 to 800 or more per month depending on your area. Use the Mortgage Payment Calculator to test different home prices, down payment amounts, and rates until you find a combination that fits comfortably within these limits. Buying below your maximum gives you a financial cushion for maintenance, emergencies, and lifestyle spending.
Frequently Asked Questions
- The 28/36 rule recommends that your monthly housing costs should not exceed 28 percent of gross monthly income, and your total monthly debt payments should stay below 36 percent. It is a guideline used by lenders and financial planners to determine a comfortable borrowing level.
- Some loan programs allow DTI ratios above 36 percent, sometimes up to 43 or 50 percent. However, higher DTI typically means higher interest rates, stricter requirements, and less financial flexibility. Aim to keep your DTI as low as possible for better terms and less stress.
- The ideal target is 20 percent to avoid PMI, but many buyers start with 3.5 to 10 percent. The key trade-off is that a smaller down payment means a larger loan, higher monthly payments, and more total interest. Setting a savings goal and timeline helps you balance getting into a home sooner versus minimizing long-term costs.