How Much Mortgage Can You Afford?

What Is Mortgage Affordability?

Mortgage affordability is the amount of home loan a borrower can reasonably manage based on their income, debts, and down payment. Lenders use standardized ratios to ensure borrowers can handle the financial commitment.

Affordability goes beyond the mortgage payment itself. It includes property taxes, homeowners insurance, and, in some cases, mortgage insurance and HOA fees. These are often bundled into your monthly housing cost.

Sources: FDIC, Rocket Mortgage

The 28/36 Rule: Front-End and Back-End Ratios

Lenders commonly use the 28/36 rule as a guideline to balance a borrower's housing costs against other debts. The rule states that housing expenses should not exceed 28% of your gross monthly income, and total monthly debt payments should not exceed 36% of your gross monthly income.

The front-end ratio focuses solely on housing-related costs, often called PITI (principal, interest, taxes, and insurance). The back-end ratio includes all monthly debt payments—housing plus other obligations like car loans, student loans, and credit card payments.

• Front-end ratio: Housing expenses ≤ 28% of gross monthly income.
• Back-end ratio: Total debt payments ≤ 36% of gross monthly income.

Sources: FDIC, Rocket Mortgage, LendingTree

How to Calculate Your Debt-to-Income Ratio

Your debt-to-income (DTI) ratio is a key number lenders use. To calculate it, sum up your monthly debt payments and divide by your gross monthly income. Multiply by 100 to get a percentage.

This tells lenders what share of your income goes toward debt. A lower DTI suggests you have more room in your budget for a mortgage payment.

• Add up all monthly debt obligations: housing costs, car loans, student loans, credit card payments, etc.
• Divide total monthly debt by gross monthly income.
• Multiply by 100 to get your DTI percentage.

Sources: FDIC, Rocket Mortgage, LendingTree

Other Factors Lenders Consider

Beyond income and DTI, lenders review your credit score, assets, and employment history to assess risk. These factors help determine whether you qualify for a loan and what interest rate you receive.

A strong profile may allow a borrower to take on a higher DTI than the typical 36% back-end limit, especially if they have compensating factors like a large down payment or substantial savings.

• Credit score: Higher scores generally improve loan terms.
• Assets: Savings and investments can serve as a cushion.
• Employment history: Stable income is important to lenders.

Sources: FDIC, Rocket Mortgage, LendingTree

How Down Payment Affects Affordability

The size of your down payment directly affects your loan amount and monthly payment. A larger down payment reduces the principal you borrow, which lowers your monthly payment and interest costs.

If your down payment is less than 20% on a conventional loan, you typically need to pay private mortgage insurance (PMI), which increases your monthly housing cost. Reaching 20% can help you avoid that extra expense.

Sources: MortgageCalculators.info, LendingTree

Additional Costs: Taxes, Insurance, PMI, HOA Fees

A mortgage payment is more than just principal and interest. Property taxes and homeowners insurance are often escrowed into the monthly payment, and if you put down less than 20% on a conventional loan, PMI is required.

Homeowners association (HOA) fees, if applicable, also add to your monthly housing cost. Lenders include these expenses when calculating your front-end ratio, so they affect how much you can borrow.

• PITI: principal, interest, taxes, and insurance.
• PMI: required on conventional loans with less than 20% down.
• HOA fees: included if your property has an association.

Sources: FDIC, MortgageCalculators.info, Rocket Mortgage, LendingTree

Worked Examples for Different Income Levels

To illustrate, let's look at two hypothetical borrowers. Assume a 30-year fixed-rate mortgage with a nominal interest rate of 6.5% (APR may differ). Property taxes and insurance are not shown here to keep the example focused on the 28% front-end limit.

Example 1: Annual income of $60,000 (gross monthly income of $5,000). The 28% front-end limit allows $1,400 per month for housing costs. At 6.5% interest, a $1,400 monthly principal and interest payment would support a loan of about $221,400.

Example 2: Annual income of $100,000 (gross monthly income of $8,333). The 28% limit allows $2,333 per month. At 6.5% interest, that supports a loan of about $368,900.

These examples do not include property taxes, insurance, or PMI. Those costs would reduce the loan amount you can afford for a given monthly payment.

Sources: FDIC, Rocket Mortgage

How to Use a Mortgage Calculator to Find Your Affordable Range

A mortgage calculator can help you estimate your price range by inputting your income, debts, and down payment. Many lenders provide affordability calculators that apply the 28/36 rule as a starting point.

To use one, enter your gross monthly income, monthly debt payments, interest rate, property tax rate, and insurance costs. The calculator will show an estimated loan amount or monthly payment you can reasonably handle. Remember, these calculators give estimates, not final loan approvals.

Sources: MortgageCalculators.info, LendingTree