Purchasing real estate with a mortgage is often the most extensive personal investment most people make. How much you can afford to borrow depends on several factors, not just what a bank is willing to lend you. You need to evaluate not only your finances but also your preferences and priorities.

Here is everything you need to consider to determine how much you can afford.

KEY TAKEAWAYS

  • The general rule is that you can afford a mortgage that is 2x to 2.5x your gross income.
  • Total monthly mortgage payments are typically made up of four components: principal, interest, taxes, and insurance (collectively known as PITI).
  • Your front-end ratio is the percentage of your annual gross income that goes toward paying your mortgage, and in general, it should not exceed 28%.
  • Your back-end ratio is the percentage of your annual gross income that goes toward paying your debts, and in general, it should not exceed 43.

How Much of a Mortgage Can I Afford?

Generally speaking, most prospective homeowners can afford to finance a property whose mortgage is between two and two-and-a-half times their annual gross income. Under this formula, a person earning $100,000 per year can only afford a mortgage of $200,000 to $250,000. However, this calculation is only a general guideline."

Ultimately, when deciding on a property, you need to consider several additional factors. First, it's a good idea to have some understanding of what your lender thinks you can afford (and how it arrived at that estimation).

Second, you need to have some personal introspection and figure out what type of home you are willing to live in if you plan on living in the house for a long time and what other types of consumption you are ready to forgo—or not—to live in your home.

 

While real estate has traditionally been considered a safe long-term investment, recessions and other disasters (like the 2020 economic crisis) can test that theory—and make would-be homeowners think twice.

How Do Lenders Determine Mortgage Loan Amounts?

While each mortgage lender maintains its own criteria for affordability, your ability to purchase a home (and the size and terms of the loan you will be offered) will always depend mainly on the following factors.

Many different factors go into the mortgage lender’s decision on homebuyer affordability, but they boil down to income, debt, assets, and liabilities. A lender wants to know how much income an applicant makes, how many demands there are on that income, and the potential for both in the future—in short, anything that could jeopardize its ability to get paid back.

Income, down payment, and monthly expenses are generally base qualifiers for financing, while credit history and score determine the rate of interest on the financing itself.

Gross Income 

This is the level of income a prospective homebuyer makes before taking out taxes and other obligations. This is generally deemed your base salary plus any bonus income and can include part-time earnings, self-employment earnings, Social Security benefits, disability, alimony, and child support.

Front-End Ratio

Gross income plays a vital part in determining the front-end ratio, also known as the mortgage-to-income ratio. This ratio is the percentage of your yearly gross income that can be dedicated toward paying your mortgage each month. The total amount of money that makes up your monthly mortgage payment consists of four components, known as PITI: principal, interest, taxes, and insurance (both property insurance and private mortgage insurance, if required by your mortgage).

A good rule of thumb is that the front-end ratio based on PITI should not exceed 28% of your gross income. However, many lenders let borrowers exceed 30%, and some even let borrowers exceed 40%.1

Back-End Ratio

Also known as the debt-to-income ratio (DTI), it calculates the percentage of your gross income required to cover your debts. Debts include credit card payments, child support, and other outstanding loans (auto, student, etc.).

In other words, if you pay $2,000 each month in debt services and you make $4,000 each month, your ratio is 50%—half of your monthly income is used to pay the debt.

However, a 50% debt-to-income ratio isn’t going to get you that dream home. Most lenders recommend that your DTI not exceed 43% of your gross income.2 To calculate your maximum monthly debt based on this ratio, multiply your gross income by 0.43 and divide by 12.

Your Credit Score

If one side of the affordability coin is income, then the other side is your debt.

Mortgage lenders have developed a formula to determine the level of risk of a prospective home buyer. The formula varies but is generally determined by using the applicant’s credit score.3 Applicants with a low credit score can expect to pay a higher interest rate, also referred to as an annual percentage rate (APR), on their loan. If you want to buy a home soon, pay attention to your credit reports. Be sure to keep a close eye on your reports. If there are inaccurate entries, it will take time to get them removed, and you don’t want to miss out on that dream home because of something that is not your fault.

The 28%/36% Rule

The 28%/36% rule is a heuristic used to calculate the amount of housing debt one should assume. According to this rule, a maximum of 28% of one's gross monthly income should be spent on housing expenses and no more than 36% on total debt service (including housing and other debt such as car loans and credit cards). Lenders often use this rule to assess whether to extend credit to borrowers. Sometimes the rule is amended to use slightly different amounts, such as 29%/41%.

How to Calculate a Down Payment Amount

The down payment is the amount that the buyer can afford to pay out-of-pocket for the residence, using cash or liquid assets. Lenders typically demand a down payment of at least 20% of a home’s purchase price, but many let buyers purchase a home with significantly smaller percentages. Obviously, the more you can put down, the less financing you’ll need, and the better you look to the bank.

For example, if a prospective homebuyer can afford to pay 10% on a $100,000 home, the down payment is $10,000, which means the homeowner must finance $90,000.

Besides the amount of financing, lenders also want to know the number of years for which the mortgage loan is needed. A short-term mortgage has higher monthly payments but is likely less expensive over the duration of the loan.

 

Homebuyers need to come up with a 20% down payment to avoid paying private mortgage insurance.4

Personal Considerations for Homebuyers

A lender could tell you that you can afford a considerable estate, but can you? Remember, the lender’s criteria look primarily at your gross pay and other debts. The problem with using gross income is simple: You are factoring in as much as 30% of your paycheck—but what about taxes, FICA deductions, and health insurance premiums. In addition, consider your pre-tax retirement contributions and college savings, if you have children. Even if you get a refund on your tax return, that doesn’t help you now—and how much will you get back?

That’s why some financial experts feel it’s more realistic to think in terms of your net income (aka take-home pay) and that you shouldn’t use any more than 25% of your net income on your mortgage payment. Otherwise, while you might be able to pay the mortgage monthly, you could end up “house poor.” 

The costs of paying for and maintaining your home could take up such a large percentage of your income—far and above the nominal front-end ratio—that you won’t have enough money left to cover other discretionary expenses or outstanding debts or to save for retirement or even a rainy day. Whether or not to be house poor is mostly a matter of personal choice; getting approved for a mortgage doesn’t mean you can afford the payments.