How Much House Can I Afford on a $100,000 Salary?

On a $100,000 salary, a common lender guideline caps your housing costs at 28% of your gross monthly income, and your total debts at 36%. At 7.4% over 30 years, the principal-and-interest payment at the 28% limit supports a loan of about $337,000. The 36% limit supports about $433,000, but only if you have almost no other debt.

Key points:

• $100,000 a year is $8,333.33 a month before taxes and deductions.
• The 28% limit covers housing only. The 36% limit covers housing plus every other monthly debt.
• Lenders use gross income, not take-home pay.
• The loan figures below are principal and interest only. Taxes and insurance reduce the room under the 28% limit.

The two numbers lenders use

Lenders measure affordability with debt-to-income ratios (DTI). Each one divides a monthly payment by your gross monthly income.

Front-end ratio. This is the housing payment: principal, interest, property taxes and homeowners insurance, often called PITI. The classic rule of thumb caps it at 28% of gross monthly income.

Back-end ratio. This is the housing payment plus every other monthly debt: car loans, student loans, credit card minimums, personal loans and child support. The rule of thumb caps it at 36%.

The 28/36 rule is a rule of thumb, not a legal limit. It is still the benchmark most buyers should test first.

What the limits are for $100,000

Gross monthly income is $100,000 ÷ 12, which is $8,333.33. Here is what the two caps mean in dollars.

Limit	Share of income	Monthly amount
Housing (front-end)	28%	$2,333.33
Total debt (back-end)	36%	$3,000.00

Fannie Mae's Selling Guide sets the back-end ratio differently depending on how the loan is approved. A manually underwritten loan starts at 36%. It can go up to 45% if the borrower has compensating factors such as a strong credit score and cash reserves. A loan approved through Fannie Mae's automated Desktop Underwriter system can go up to 50% with the right compensating factors.

Those higher limits are real, but they are not guaranteed. A higher ratio means less margin for a bad month, so think about the 36% number as your practical ceiling.

A worked example at 7.4% for 30 years

This example uses 7.40%: Freddie Mac's Primary Mortgage Market Survey put the average 30-year fixed rate at 7.40% for the week of October 15, 2026.

Here is the most you could borrow, counting principal and interest only:

Scenario	Maximum monthly principal and interest	Maximum loan
28% front-end limit	$2,333.33	$337,001.80
36% back-end limit	$3,000.00	$433,288.03

Read the first row carefully. The $2,333.33 is the total housing budget under the 28% rule, and taxes and insurance come out of it too. So the real loan you can carry at the 28% limit is smaller than $337,001.80, depending on your property tax bill and insurance premium.

Now test a real home. A $420,000 home with 10% down needs a $378,000 loan. At 7.4% over 30 years, the principal and interest is $2,617.20 a month. That is above the $2,333.33 front-end figure before you add taxes and insurance. It fits under the $3,000.00 back-end figure only if your other monthly debts are small.

You can run your own version with the affordability calculator. Enter your gross monthly income, the percentage you want to test, the rate and the term.

Here is a check you can run yourself. A $337,001.80 loan at 7.4% over 30 years has a monthly principal and interest payment of $2,333.33, which is exactly the 28% figure for this salary. Work backward from the payment and you get the loan. Work forward from the loan and you get the payment. Both directions should match, and if they do not, a rate or term in your calculation is off.

Remember that the rate in this example is an average, not an offer. A borrower with a strong credit profile may be quoted a lower rate, and one with a weaker profile a higher rate. Change the rate in the calculator to see how much the loan shrinks or grows at the same payment.

What counts against you

Lenders add up more than your salary. Here are the items that usually reduce how much you can borrow:

• Car loans and student loans. Each monthly payment counts toward the back-end ratio, even if you plan to pay it off soon.
• Credit card minimums. Lenders use the minimum payment on the statement, not what you usually pay.
• Child support and alimony. These are counted as debts.
• Property taxes and insurance. These sit inside the 28% front-end figure, so a high-tax county reduces your loan amount even with the same income.

Two other points affect the answer. First, your credit score can change the rate you are offered, and a higher rate shrinks the loan at the same payment. Second, your down payment and closing costs must come from savings. A larger down payment on the same house lowers the loan and the monthly payment, which improves both ratios.

How to make the number work for you

1. Start with the back-end limit, then subtract your existing debts. If your debts already take a large share of the 36%, the room for a mortgage is smaller than the headline figure.
2. Price taxes and insurance for the actual home. Ask the listing agent for the property tax history, and get an insurance quote early. These two costs decide whether a house fits the 28% budget.
3. Compare the monthly payment, not only the price. A $378,000 loan at 7.4% and a $337,000 loan at the same rate have very different monthly costs. Pick the one that leaves room in your budget for repairs and savings.
4. Get a pre-approval before you shop. A lender will confirm your actual DTI and your rate, which is more reliable than any rule of thumb.

Use the affordability calculator to test a range of prices, not a single number. Try the price you want, then a price 10% lower and a price 10% higher. Watch how the monthly payment moves. That gives you a realistic band to take into a lender's office.

Sources

• Fannie Mae Selling Guide, B3-6-02, debt-to-income ratios: https://selling-guide.fanniemae.com/sel/b3-6-02/debt-income-ratios
• Freddie Mac, Primary Mortgage Market Survey (PMMS): https://www.freddiemac.com/pmms