What lenders will approve you for
On a $100,000 salary, most lenders will approve you for a mortgage between $300,000 and $420,000, depending on your down payment, credit score, and existing debt. The standard rule is that your monthly housing payment should not exceed 28% of your gross monthly income — that's about $2,333 per month on $100,000 a year. A second rule, called the debt-to-income ratio, caps your total monthly debt payments (mortgage, car loans, credit cards, student loans) at 43% of gross income, or about $3,583.
These are lender maximums, not recommendations for what you should actually spend. A lender will approve you for the highest amount they can legally lend; your job is to decide what you can actually afford to pay back without financial strain.
The actual price you can pay depends heavily on your down payment. With 20% down ($84,000 on a $420,000 house), you avoid private mortgage insurance (PMI) and get better interest rates. With 5% down ($21,000), you pay PMI on top of your mortgage, taxes, and insurance, which raises your monthly cost significantly. With 3% down ($12,600), your monthly payment climbs even higher.
Key Takeaways
- Lenders typically approve borrowers making $100,000 annually for mortgages between $300,000 and $420,000, but approval is not the same as affordability.
- Your housing payment should not exceed 28% of your gross monthly income ($2,333), and your total debt payments should stay below 43% of gross income ($3,583).
- A 20% down payment eliminates PMI and lowers your monthly cost; anything less than 20% adds insurance premiums to your payment.
- Your credit score, existing debt, interest rates, and local property taxes all shift what you can realistically afford within the lender-approved range.
- The difference between what a lender approves and what leaves you with breathing room for emergencies and savings is often $100,000 or more.
How down payment size changes your monthly payment
Assume a $350,000 house purchase, a 7% interest rate, and a 30-year mortgage. The monthly payment (principal and interest only) varies sharply by down payment:
| Down Payment | Loan Amount | Monthly P&I | PMI (if under 20%) | Total with PMI |
|---|---|---|---|---|
| 20% ($70,000) | $280,000 | $1,864 | $0 | $1,864 |
| 10% ($35,000) | $315,000 | $2,098 | ~$190 | ~$2,288 |
| 5% ($17,500) | $332,500 | $2,215 | ~$265 | ~$2,480 |
| 3% ($10,500) | $339,500 | $2,263 | ~$325 | ~$2,588 |
This table shows principal and interest only. Your actual monthly payment also includes property taxes, homeowners insurance, and possibly HOA fees. On a $350,000 house in a moderate-tax state, add $400 to $600 per month for taxes and insurance combined. In high-tax areas like New Jersey or Illinois, add $800 to $1,200.
PMI typically runs 0.5% to 1.5% of your loan amount annually, divided into monthly payments. You can remove it once you reach 20% equity, but that takes years. Putting down less than 20% is sometimes necessary, but it permanently raises your monthly cost until you refinance or pay down the principal.
What your existing debt does to your buying power
The 43% debt-to-income rule includes everything: your new mortgage payment plus car loans, student loans, credit card minimums, and any other monthly obligations. If you make $100,000 annually ($8,333 gross per month), your total debt payments cannot exceed $3,583.
If you already carry $800 in car payments and $300 in student loan payments, you have only $2,483 left for housing. That $2,483 must cover principal, interest, property taxes, insurance, and PMI — which means you can afford a smaller house than someone with no existing debt.
Paying down debt before buying is one of the highest-return moves you can make. Eliminating a $400 car payment frees up $400 of your housing budget immediately. Paying off credit cards does the same. If you have six months before you plan to buy, focusing on debt reduction often increases your buying power by $50,000 to $100,000.
How interest rates and credit score affect what you pay
Interest rates move constantly and vary by credit score. On a $280,000 loan (20% down on a $350,000 house), the difference between a 6.5% rate and a 7.5% rate is about $150 per month — $1,800 per year. Over 30 years, that's $54,000 more in total interest.
Your credit score determines which rates you may have access to for. A score above 760 typically gets the best rates available that week. A score between 700 and 759 costs 0.25% to 0.5% more. A score below 700 costs significantly more, and below 620 makes conventional financing difficult or impossible.
If your score is below 740, spending three to six months paying down balances and making on-time payments can raise it enough to save thousands. A 50-point increase might lower your rate by 0.25%, which saves $70 per month on a $280,000 loan.
Property taxes and insurance vary by location
A $350,000 house in Texas might cost $300 per month in property taxes; the same house in New Jersey might cost $900. Insurance varies by state, age of the house, and local risk factors. These costs are not optional and are often underestimated by first-time buyers.
Before you decide on a price range, research the property tax rate and average insurance cost in the specific area you are considering. Many county assessor websites show tax rates by neighborhood. Insurance companies will quote you based on the address and the house details. Adding these to your principal-and-interest payment gives you the true monthly cost.
In some high-tax areas, property taxes and insurance can equal 40% of your total monthly payment. In low-tax areas, they might be 20%. This difference alone can shift your affordable price range by $50,000 to $100,000.
The gap between what you can afford and what lenders approve
A lender will approve you for $420,000 because the math works on paper. But that approval assumes you have no emergencies, no job changes, no medical bills, and no desire to save money. It also assumes interest rates stay the same and you never want to take a vacation or replace your car.
A safer target is 25% of your gross monthly income for housing ($2,083 on $100,000 salary), which leaves room for property taxes, insurance, maintenance, and life. At that level, you can afford a house in the $280,000 to $320,000 range with 20% down, depending on your interest rate and location.
The difference between the lender maximum ($420,000) and a sustainable purchase ($300,000 to $320,000) is real money. It is the difference between being house-poor and having financial flexibility. Most financial advisors recommend staying well below the lender maximum, especially if you have student loans, plan to start a family, or want to retire before age 70.
Frequently Asked Questions
Can I afford a $400,000 house on $100,000 salary?
Lenders may approve you for it if you have 20% down and no other debt, but your monthly payment would be around $2,500 to $2,700 before taxes and insurance. With taxes and insurance, you could easily hit $3,200 to $3,500 per month — leaving little room for emergencies or savings. It is technically possible but financially tight.
What if I have student loans or a car payment?
Every $100 in existing monthly debt reduces your housing budget by $100. If you have $500 in student loans and a $300 car payment, you have only $2,283 left for housing instead of $2,583. Pay down these debts before buying if you can, or plan to buy a less expensive house.
Does my down payment have to be 20%?
No. You can put down 3%, 5%, 10%, or any amount up to 100%. Anything below 20% triggers PMI, which adds $150 to $400 per month depending on the loan size. If you do not have 20% saved, a smaller down payment is better than waiting indefinitely, but understand that PMI raises your monthly cost.
How much should I actually spend if I want financial breathing room?
Aim for a house that costs no more than 25% of your gross monthly income ($2,083 on $100,000 salary). This typically means a purchase price of $280,000 to $320,000 with 20% down, depending on your interest rate and location. This leaves room for emergencies, maintenance, and savings.
What if interest rates drop after I buy?
You can refinance to a lower rate and lower your monthly payment. Refinancing costs $2,000 to $5,000 in fees, so it makes sense only if the rate drop is at least 0.5% and you plan to stay in the house long enough to recoup those fees — usually two to three years.