The 28/36 rule: what lenders actually use

Most lenders follow the 28/36 rule when deciding how much house payment you can afford. The rule says your monthly mortgage payment (including property taxes, insurance, and HOA fees if you have them) should not exceed 28% of your gross monthly income. Your total debt payments—mortgage, car loans, credit cards, student loans, everything—should not exceed 36% of your gross monthly income.

This is not a law. It is the standard that banks, credit unions, and mortgage companies use to decide whether to lend you money. If you make $5,000 per month gross, lenders will typically approve a mortgage payment up to $1,400 (28% of $5,000). If your other debts total $500 per month, you have $300 left in your 36% budget before the lender stops.

Some lenders will go higher—up to 43% of gross income on the total debt ratio—if you have a large down payment, excellent credit, or stable income history. Others will go lower if you are self-employed, have recent late payments, or carry high credit card balances. The 28/36 rule is the baseline, not a ceiling.

Key Takeaways

  • Your mortgage payment should not exceed 28% of your gross monthly income, according to the standard lenders use.
  • Your total monthly debt payments (mortgage plus everything else) should stay under 36% of gross income.
  • Lenders may approve higher amounts if you have a large down payment and strong credit, or deny you at lower amounts if you have recent missed payments.
  • Your actual affordable payment depends on your other debts, property taxes in your area, and whether you are putting down 20% or less (which adds mortgage insurance).
  • A payment that fits the 28/36 rule may still strain your budget if you have irregular income, high childcare costs, or medical expenses.

How to calculate your personal 28% number

Start with your gross monthly income—the amount you earn before taxes, not your take-home pay. If you are paid annually, divide by 12. If you are paid biweekly, multiply by 26 and divide by 12. If your income varies month to month, use an average of the last two years or the amount a lender would use (often the lower of the last two years for self-employed people).

Multiply that number by 0.28. That is your target maximum for housing payment. If you make $4,000 gross per month, your housing payment should not exceed $1,120. That $1,120 includes your principal and interest, property taxes, homeowners insurance, and mortgage insurance (if your down payment is less than 20%). It does not include utilities, maintenance, or HOA fees that are separate line items.

If you are married or applying jointly, add both incomes together before multiplying. A household with one person earning $3,500 and another earning $2,500 has $6,000 gross income, so the housing payment target is $1,680.

What happens when you exceed the 28% threshold

If your housing payment would be more than 28% of your gross income, most lenders will deny your mortgage application or require you to put down more money upfront. Some will approve you if you lower your target home price, increase your down payment, or pay off other debts first.

If you somehow buy a house with a payment above 28%—perhaps you paid cash and later took out a loan, or a lender bent the rules—you are at higher risk of missing payments during job loss, medical emergency, or income drop. Lenders use the 28% threshold because they know from decades of data that payments above that level have higher default rates.

The 36% total debt rule exists for the same reason. If your mortgage plus car payment plus credit cards plus student loans add up to more than 36% of income, you have little cushion for unexpected costs. One job interruption or medical bill can push you into default.

Factors that change what you can actually afford

The 28/36 rule is a lender's tool, not a personal budget tool. A payment that passes the rule may still be too high for your actual life. Consider these real costs that the rule does not account for:

  • Property taxes vary by location. A $300,000 house in New Jersey might have a $6,000 annual property tax bill, while the same house in Texas might be $3,000. That difference is $250 per month in your housing payment, even though the purchase price is identical.
  • Mortgage insurance adds cost if you put down less than 20%. A $300,000 house with 10% down ($30,000) will have a mortgage insurance premium of roughly $150 to $300 per month, depending on your credit score and the loan type. That premium stays until you reach 20% equity.
  • Homeowners insurance is not the same everywhere. Insurance in flood zones, high-crime areas, or areas with frequent hurricanes costs significantly more than insurance in low-risk areas.
  • Maintenance and repairs are not optional. Lenders do not include these in the housing payment calculation, but a roof replacement, water heater failure, or foundation crack can cost thousands. Financial advisors often recommend setting aside 1% of the home's purchase price per year for maintenance.
  • Your income may not be stable. If you are self-employed, work on commission, or have seasonal income, a payment that fits the rule during a good year may crush you during a slow year. Lenders know this and often use a lower income figure for self-employed borrowers.

The difference between what lenders allow and what you should spend

A lender saying you can afford a $1,500 payment does not mean you should spend $1,500. Lenders care about whether you will default; they do not care whether you will have money left over for groceries, childcare, or emergencies.

Many financial advisors recommend a stricter personal rule: keep your housing payment to 25% of gross income, not 28%. This leaves more room for other debts, savings, and unexpected costs. If you have irregular income, high childcare costs, or plan to have children soon, 25% is a safer target than 28%.

Before you commit to a mortgage amount, write down your actual monthly expenses: utilities, insurance, food, transportation, childcare, student loan payments, credit card minimums, and anything else you spend money on. Add your target housing payment to that list. If the total is more than 70% to 75% of your gross income, you are leaving yourself too little room to save or handle emergencies.

How down payment size affects your affordable payment

The amount you put down changes how much house payment you can afford, because it changes the size of the loan and whether you pay mortgage insurance.

If you put down 20% or more, you avoid mortgage insurance entirely. A $300,000 house with $60,000 down (20%) means a $240,000 loan. A $300,000 house with $30,000 down (10%) means a $270,000 loan plus mortgage insurance. The larger loan and the insurance premium together make the second payment significantly higher, even though the house costs the same.

Putting down more money upfront lowers your monthly payment and gets you out from under mortgage insurance faster. It also means you need less income to pass the 28% test. If you are close to the lender's income threshold, a larger down payment can be the difference between approval and denial.

When to talk to a lender before house hunting

Before you start looking at houses, get a pre-qualification or pre-approval letter from a lender. Pre-qualification is informal—the lender asks about your income and debts but does not verify anything. Pre-approval is formal—the lender pulls your credit report, verifies your income with your employer or tax returns, and confirms you can borrow a specific amount.

A pre-approval letter tells you the maximum loan amount a lender will give you. That amount is based on the 28/36 rule, your credit score, your down payment, and your debt history. It is not a recommendation of what you should spend; it is a ceiling of what the lender will lend.

Use the pre-approval number as a starting point, then apply your own 25% rule or whatever percentage feels safe for your situation. If a lender pre-approves you for $350,000, that does not mean you should buy a $350,000 house. It means you could borrow up to that amount if you wanted to. Your actual comfortable purchase price may be $50,000 to $100,000 lower.

Frequently Asked Questions

What if my income is irregular or seasonal?

Lenders typically average your income over the last two years for self-employed people or those with variable income. Some use the lower of the last two years to be conservative. If you earned $60,000 last year and $50,000 this year, the lender may use $50,000 as your income for the mortgage calculation. Tell the lender upfront if your income varies; they will ask for tax returns and bank statements to verify.

Can I include my spouse's income if we are not married?

No. Lenders will only count income from people who are on the loan. If you are married or in a civil union, both incomes count. If you are unmarried, only your income counts, even if you live together and share expenses. You can have a co-borrower who is not a spouse, but they must be on the mortgage note.

Does the 28% rule include property taxes and insurance?

Yes. The 28% rule covers your principal and interest payment, property taxes, homeowners insurance, and mortgage insurance (if applicable). It does not include utilities, HOA fees (if separate), or maintenance costs. When a lender calculates your housing payment for the 28% test, they estimate property taxes and insurance based on the home's location and value, then add those to your loan payment.

What if I have a lot of student loan debt?

Student loans count toward your 36% total debt ratio. If you owe $400 per month in student loans and $300 per month in car payments, that is $700 in debt before your mortgage even starts. On a $5,000 gross monthly income, you have $1,800 available for total debt (36% of $5,000), which leaves only $1,100 for your housing payment. Paying down student loans before you buy can increase the housing payment you can afford.

Should I buy the maximum amount the lender approves?

No. The lender's approval is based on whether you will default, not on whether the payment fits your actual budget. Many people buy at the maximum and then struggle to pay for maintenance, childcare, or emergencies. A safer approach is to buy at 80% to 90% of the approved amount, or to use your own 25% rule instead of the lender's 28% rule.