What lenders will actually lend you
The size of a home loan you can get depends on three things: your income, your debts, and the value of the home you want to buy. Lenders use these to calculate how much monthly payment you can afford, then work backward to a loan amount. The maximum is not the same as what you should borrow — lenders will often approve you for more than is comfortable to repay.
Most lenders use a debt-to-income ratio, which compares your total monthly debt payments to your gross monthly income. A typical limit is 43 percent, meaning if you earn $5,000 a month before taxes, your total debts (including the new mortgage) cannot exceed $2,150. Some lenders go as high as 50 percent for borrowers with strong credit and savings, but 43 is the standard.
The home's value also sets a ceiling. You cannot borrow more than the home is worth — lenders require an appraisal to confirm the price. If you are putting down 20 percent, a $300,000 home means a maximum loan of $240,000. If you put down less, the loan is smaller still, though you will pay mortgage insurance on top.
Key Takeaways
- Lenders calculate your maximum loan by dividing your total monthly debts (including the new mortgage) by your gross monthly income, aiming for a ratio of 43 percent or lower.
- Your down payment size directly affects the loan amount — a larger down payment means you borrow less, even for the same home price.
- Credit score, savings, and employment history all influence whether a lender will approve you at the maximum ratio or require a lower one.
- The home's appraised value sets the upper limit on what you can borrow, regardless of the price you agreed to pay.
- Being approved for a loan amount is not the same as being able to afford the monthly payment comfortably over 30 years.
How lenders calculate your maximum loan amount
Start with your gross monthly income — the amount before taxes and deductions. If you are salaried, divide your annual salary by 12. If you are self-employed or have variable income, lenders typically average the last two years of tax returns. If you have been in your current job for less than two years, some lenders will use only the most recent year.
Next, list all your monthly debt payments: car loans, student loans, credit card minimums, child support, and any other obligations that appear on your credit report. Do not include utilities, groceries, or insurance — only debt. Add the estimated mortgage payment for the home you want to buy (lenders use a formula that includes property taxes, homeowners insurance, and mortgage insurance if your down payment is under 20 percent).
Divide that total by your gross monthly income. If the result is 43 percent or lower, you meet the standard threshold. Multiply your gross monthly income by 0.43 to find the maximum total debt payment the lender will allow. Subtract your existing debts from that number, and what remains is the maximum monthly mortgage payment you can carry. A mortgage calculator can then convert that payment into a loan amount, though the lender will do this calculation for you.
Why your down payment size matters
A larger down payment reduces the loan amount you need, even if you are buying the same home. If you are buying a $300,000 home and put down 10 percent ($30,000), you borrow $270,000. If you put down 20 percent ($60,000), you borrow $240,000. The smaller loan means a smaller monthly payment, which improves your debt-to-income ratio and may allow you to buy a more expensive home overall.
Down payments under 20 percent also trigger private mortgage insurance (PMI), an extra monthly cost that protects the lender if you default. PMI typically costs 0.5 to 1.5 percent of the loan amount per year, added to your monthly payment. This cost makes the monthly payment higher than it would be with 20 percent down, which in turn reduces the maximum loan amount a lender will approve.
If you have saved $40,000 and are deciding between a $300,000 home with 13 percent down or a $250,000 home with 16 percent down, the second option will have a lower monthly payment and no PMI, even though you are borrowing less total. The trade-off is the home price itself.
How credit score and employment history affect approval
Your credit score tells the lender how reliably you have paid past debts. Scores above 740 typically may have access to for the best interest rates and the highest debt-to-income ratios (up to 50 percent). Scores between 620 and 739 usually may have access to at the standard 43 percent. Scores below 620 may face higher rates or stricter limits, or may not be approved at all.
Employment history also matters. Lenders want to see at least two years in your current field, though not necessarily at the same employer. If you changed jobs recently, they may ask for a letter from your new employer confirming your salary and position. Self-employed borrowers face more scrutiny — most lenders require two years of tax returns and may average income across both years, which can lower your approved amount if your income is rising.
Savings and assets strengthen your application. If you have six months of mortgage payments in the bank, lenders may approve you at a higher ratio or offer better terms. This is called reserves, and it signals you can weather a job loss or emergency without defaulting.
The difference between maximum approval and what you can afford
A lender may approve you for a $400,000 loan, but that does not mean you should take it. The 43 percent debt-to-income ratio is a legal limit for most lenders, not a comfort threshold. Many financial advisors recommend keeping your total housing payment (mortgage, taxes, insurance, and PMI) to 28 percent of gross income, which is lower than the 43 percent total debt limit.
Consider also what happens if interest rates rise, property taxes increase, or your income drops. A $400,000 loan at 6 percent interest costs roughly $2,400 a month in principal and interest alone — add property taxes, insurance, and PMI, and you may be at $3,200 or more. If you lose your job or face a medical emergency, that payment becomes unaffordable quickly.
A useful rule of thumb: borrow the amount that leaves you comfortable with your monthly payment, not the maximum the lender will allow. This usually means aiming for a home price that is 2.5 to 3 times your gross annual income, though this varies by local home prices and your personal situation.
What happens if you do not meet the standard ratio
If your debt-to-income ratio exceeds 43 percent, you have a few options. The first is to pay down existing debts — even paying off a car loan or credit card can lower your ratio enough to may have access to. The second is to increase your income, though lenders will not count a new job until you have been there two years (with rare exceptions for promotions in the same field).
The third option is to look for a co-borrower, usually a spouse or family member, whose income can be added to yours. Their debts are also added, so this only helps if their income is significantly higher than their debts. The fourth option is to save a larger down payment, which reduces the loan amount and the monthly payment, improving your ratio.
Some lenders offer non-traditional programs for borrowers who do not fit the standard mold — for example, bank statement loans for self-employed people, or loans that count rental income or alimony. These typically come with higher interest rates and stricter down payment requirements, but they exist if the standard path is closed to you.
How to estimate your loan amount before talking to a lender
Use an online mortgage calculator to get a rough number. Enter your down payment amount, the interest rate (use the current average for your credit range), the loan term (usually 30 years), and your estimated property taxes and insurance. The calculator will show you the monthly payment. Then divide that payment by your gross monthly income to see where you stand on the debt-to-income ratio.
Do this for a few different home prices to see where the ratio hits 43 percent. That is roughly your maximum. Then subtract 10 to 15 percent from that number to find a price that feels sustainable. This gives you a target range to discuss with a lender, who will run the actual numbers with your real income and debts.
When you are ready to move forward, get pre-approved (not just pre-may have access to) by a lender. Pre-approval means they have verified your income, credit, and debts and are willing to lend you a specific amount. Pre-qualification is just an estimate. Pre-approval is what sellers take seriously, and it also locks in an interest rate for a set period, usually 60 to 90 days.
Frequently Asked Questions
Can I borrow more if I have a co-signer?
Yes, if the co-signer has strong income and low debts. Their income is added to yours, but their debts are also counted. A spouse with high income and no debts can significantly raise your maximum. A family member with their own debts may not help much.
What if the home appraises for less than the purchase price?
You cannot borrow more than the appraised value. If you agreed to pay $300,000 but it appraises at $280,000, the lender will only lend 80 percent of $280,000 (if you put down 20 percent). You either pay the difference in cash or renegotiate the price with the seller.
Does a larger down payment mean I can borrow more total?
No — a larger down payment reduces the loan amount for the same home. However, it may improve your debt-to-income ratio enough to may have access to for a more expensive home overall, because the monthly payment is lower.
How long does pre-approval take?
Most lenders provide pre-approval within one to three business days if you submit documents quickly. They will ask for recent pay stubs, tax returns, bank statements, and a list of debts. Having these ready speeds up the process.
Will shopping around for rates hurt my credit score?
Multiple mortgage inquiries within 14 to 45 days (depending on the scoring model) count as a single inquiry, so shopping around does not significantly damage your score. Hard inquiries do lower your score slightly, but the effect fades within a few months.