The size of mortgage you can qualify for depends primarily on your income, your existing debts, your credit score, and the loan program you choose. Most lenders use a simple ratio: your total monthly debt payments (including the new mortgage) should not exceed 36% to 50% of your gross monthly income, depending on the loan type and how strong the rest of your application looks. A borrower earning $7,000 per month with no other debts could potentially qualify for a much larger loan than someone earning the same amount but carrying $800 in car and student loan payments.
How Lenders Decide Your Maximum Loan
Lenders don’t just look at the mortgage payment itself. They calculate your full monthly housing cost, known as PITI: principal, interest, property taxes, homeowners insurance, and, if applicable, private mortgage insurance (PMI) and homeowners association dues. That total is then measured against your gross monthly income (your pay before taxes and deductions) to produce your debt-to-income ratio, or DTI.
There are two versions of this ratio. The front-end ratio compares only your housing costs to your income. The back-end ratio adds in all your other monthly debt obligations: car loans, student loans, credit card minimum payments, personal loans, and child support. The back-end ratio is the one that matters most. If your gross monthly income is $8,000 and your total monthly debts including the proposed mortgage payment would be $3,200, your back-end DTI is 40%.
DTI Limits by Loan Program
Different loan programs set different ceilings on how high your DTI can go, which directly controls how large a mortgage you can carry.
For conventional loans (the most common type, not backed by a government agency), Fannie Mae’s standard maximum DTI is 36% for manually underwritten loans. Borrowers with stronger credit scores and cash reserves can qualify with a DTI up to 45%. When the loan runs through Fannie Mae’s automated underwriting system, the ceiling can stretch to 50%, though you’ll need solid compensating factors like a high credit score or a large down payment to get approved at that level.
FHA loans, which are insured by the Federal Housing Administration and popular with first-time buyers, are generally more flexible. Most borrowers qualify with a DTI of 50% or less, and some lenders approve ratios slightly above that with strong compensating factors. This flexibility is one reason FHA loans allow buyers with thinner financial profiles to qualify for a larger mortgage than they might get through a conventional program.
VA loans, available to eligible veterans and active-duty service members, don’t impose a hard DTI cap. Lenders typically use 41% as a guideline but can approve higher ratios when the borrower’s overall financial picture supports it.
A Quick Way to Estimate Your Number
You can get a rough idea of your maximum mortgage by working backward from your income. Start with your gross monthly income and multiply it by the DTI limit you’re likely to hit (0.43 is a reasonable middle ground for most borrowers). Then subtract your existing monthly debt payments. The result is the maximum monthly housing payment a lender would likely approve.
For example, if you earn $6,500 per month gross and have $400 in existing debts:
- $6,500 × 0.43 = $2,795 (maximum total monthly debt)
- $2,795 − $400 = $2,395 (maximum housing payment including taxes and insurance)
From there, you need to back out estimated property taxes, homeowners insurance, and PMI if your down payment is less than 20%. If those costs eat up $600 per month, you have about $1,795 left for principal and interest. At a 6.5% interest rate on a 30-year fixed mortgage, that translates to roughly $285,000 in loan amount. Change the rate to 7.5% and that same payment only supports about $257,000. The interest rate you receive has a significant impact on how much house your income can buy.
How Your Credit Score Changes the Math
Your credit score doesn’t directly set a loan amount cap, but it controls the interest rate lenders offer you, which in turn determines how much borrowing power your monthly payment gives you. According to the Consumer Financial Protection Bureau, a borrower with a 700 credit score might see loan offers starting around 5.875%, while someone with a 625 score could face rates as high as 8.875%.
The dollar difference is dramatic. On a $360,000 loan over 30 years, the borrower with the lower credit score could pay over $264,000 more in interest over the life of the loan. But the immediate effect on qualification is just as important: a higher rate means a bigger chunk of each monthly payment goes to interest rather than principal, so you qualify for a smaller loan with the same income. Improving your credit score before applying can effectively increase your purchasing power by tens of thousands of dollars without earning a penny more.
Conforming Loan Limits
Even if your income and DTI support a large mortgage, there’s an upper boundary on what counts as a standard (conforming) loan. The Federal Housing Finance Agency sets this limit annually. For 2026, the baseline conforming loan limit for a single-unit property is $832,750 in most of the country, with higher caps in designated high-cost areas.
If you need to borrow more than the conforming limit, you’ll need a jumbo loan, which typically requires a higher credit score, a larger down payment (often 10% to 20% minimum), and lower DTI ratios. Jumbo loans also tend to carry slightly higher interest rates, though the gap varies by lender and market conditions.
What Else Lenders Look At
DTI and credit score do most of the heavy lifting, but lenders also weigh several other factors when determining your maximum mortgage size.
Down payment: A larger down payment reduces the loan amount you need and eliminates PMI once you reach 20% equity, which lowers your monthly housing cost and can help you qualify for a bigger loan. FHA loans require as little as 3.5% down, and some conventional programs allow 3%, but putting down less means higher monthly costs that eat into your DTI room.
Cash reserves: Lenders like to see that you have several months of mortgage payments saved after closing. Strong reserves can be the difference between getting approved at a 45% DTI versus being capped at 36%.
Employment stability: Most lenders want to see at least two years of consistent income. If you’re self-employed, expect to provide two years of tax returns, and lenders will average your net income over that period rather than using your best year.
Loan term: A 15-year mortgage has higher monthly payments than a 30-year loan for the same amount, so choosing a shorter term reduces the loan size you qualify for. Most borrowers opt for 30-year terms to maximize their borrowing capacity, even if they plan to pay it off faster.
Getting a Reliable Answer
The estimates above give you a useful ballpark, but the only way to know your exact qualifying amount is to get preapproved by a lender. During preapproval, a loan officer pulls your credit, verifies your income and debts, and runs your profile through their underwriting system. You’ll receive a preapproval letter stating the maximum loan amount you qualify for, which also strengthens your position when making offers on homes.
Getting preapproved by two or three lenders is worth the effort. Each lender may offer a different rate or interpret your income slightly differently, especially if you have variable income, bonuses, or rental income. A small difference in the offered rate can shift your qualifying amount by $10,000 to $30,000. Multiple credit inquiries for the same type of loan within a 14- to 45-day window (depending on the scoring model) count as a single inquiry on your credit report, so shopping around won’t hurt your score.