How Much House Can You Afford on $120K in St. Louis at 7%?

The Math: $120K Salary → $327K–$426K Home

Lenders start from your gross monthly income — $10,000 on $120,000 — and apply two limits: what your housing payment can be, and what all of your debts together can be. The low end of the range keeps your full payment at 28% of gross income. The high end is what most lenders would approve at a 43% total debt-to-income ratio, assuming about $650 a month in other debts (car, student loans, credit cards).

All figures use the assumptions listed in How these numbers are calculated below.

Your Monthly Payment on a $375K Home

Here is the full payment on a $375,000 home — the middle of your range — with conventional, 5% down:

That is 32% of your gross monthly income. It doesn’t include utilities or maintenance — plan on 1–2% of the home’s value per year, or about $312–$625 a month, for upkeep.

$120K: The West County Stretch Question

At $120K, your lender maximum reaches the median price in Ballwin (63021, Rockwood schools) and Glendale/Kirkwood (63122, Kirkwood schools), both around $420,000. Your comfortable budget is closer to Fenton and Wentzville. The difference between the two is real money:

• A $420,000 home with 5% down: about $3,561 a month.
• A $335,000 home (the Fenton median): about $2,840 a month.
• That's about $721 a month more for the West County option.

Whether that's worth it depends on what you're paying for — a specific school district, commute or neighborhood — and whether you can still save for retirement at the higher payment. A conventional loan with 10% down narrows the gap by lowering both principal and PMI.

Stretching $120K Further: MHDC Assistance Plus a Seller-Paid Buydown

At $120K you’re over First Place’s limit for a 1–2 person household ($113,500), but you can still qualify through Next Step — up to $136,200 for 1–2 people, and open to repeat buyers — or through First Place with a household of three or more ($130,525). That means you can often stack two kinds of help: MHDC cash assistance (up to 4% of the first mortgage) goes toward your down payment, and a seller concession you negotiate in the offer pays to buy down your interest rate. Here is what that looks like on a $375,000 home with a 3% seller concession ($11,250):

Which buydown? The 2-1 buydown gives you the bigger break — about $458 a month in year one — while you settle in, but lenders qualify you at the full 7% rate, so it doesn’t raise your budget. The permanent buydown saves less each month (about $186) but lasts for the life of the loan and raises what you can be approved for.

Watch the lender fees. MHDC lets lenders charge an origination fee of up to 1% on these loans, which can make the 4% work out closer to 3%. Ask: “After your fees, how much of the 4% actually reduces my cash to close?”

Making it work: ask for the concession in your offer — with less than 10% down, conventional loans cap seller contributions at 3% of the price, which is exactly what’s modeled here. MHDC requires its written approval for buydowns on First Place loans, so have your MHDC-approved lender confirm the structure (for First Place or Next Step) before you write the offer. MHDC sets its own rate daily and it may be below 7%; these numbers use 7% to stay conservative. Purchase-price limits apply: $566,354 for a single-family home under First Place outside targeted areas, $692,211 under Next Step or in targeted areas. See our MHDC guide for the full rules.

Where $120K Lines Up With Recent St. Louis Sale Prices

These are the highest-volume ZIP codes where the median sale price falls within reach of a $120K budget, based on 7,006 residential sales in 2025–2026 (MARIS MLS; excludes new construction and condos). A median is a midpoint — every area has homes above and below it.

About this data: The prices and market numbers here come from 7,006 MARIS closed sales across 79 St. Louis-area ZIP codes, 2025–2026. They don’t reflect price changes since then. I’m refreshing this data at the end of 2026 and every six months after that.

Much of your list falls below your comfortable budget: St. Peters and St. Charles, South County's 63129 and Concord, Affton and Arnold. O'Fallon and Wentzville line up with it. Ballwin South and Glendale/Kirkwood are your stretch options: about $420K medians, 5 days on market, and roughly half selling the first weekend.

School districts follow addresses, not ZIP codes — always verify the district for a specific property. See the St. Louis school district guide.

How Your Debts Change the $120K Number

Every dollar of monthly debt payment is a dollar lenders won’t let you spend on housing. On $120K with conventional, 5% down:

An extra $500 a month in payments — a second car, say — costs you about $58,000 in buying power. Paying one off before you apply works the other way.

Cash You’ll Need to Close on $375K

Sellers can contribute toward closing costs, and lenders and assistance programs may offer credits — ask before assuming you need the full amount in cash. Keep an emergency fund after closing.

Example: $120K With Student Loans

Illustrative example, not a client story. A buyer earns $120,000 and pays $650 a month toward student loans and a car.

• Comfortable target: about $327K.
• Lender's likely maximum: about $426K.
• If the student loans were on an income-driven plan with a lower payment, the lender maximum could rise — but lenders have specific rules for income-driven and deferred loans, so get this reviewed early.
• Cash to close at $375K: about $30,000 with 5% down, or $48,750 with 10% down.

$120K Buyer Mistakes

Stretching to West County without pricing the alternative. Run the payment on the stretch home and on a comfortable one side by side, then decide.

Assuming a district from a ZIP code. ZIP codes and school district lines don't match. Verify the specific address before you make an offer.

Putting every dollar into the down payment. Keep three to six months of expenses after closing. A slightly larger loan is better than no emergency fund.

Forgetting older homes' systems. Many Kirkwood and Webster Groves homes are 60+ years old; budget for electrical, sewer and foundation surprises.

$120K Affordability Questions

How much house can I afford on $120K in St. Louis?

About $327K comfortably and up to about $426K with typical debts, using a conventional loan with 5% down at the rate assumed on this page.

Can I afford Kirkwood or Ballwin on $120K?

At the top of your range. Recent medians in Glendale/Kirkwood (63122) and Ballwin South (63021) are about $420,000, near the lender's maximum for a $120K buyer with typical debts.

Should I put 10% down instead of 5%?

If you can do it and still keep an emergency fund, yes — it lowers both the loan and PMI. Don't empty your savings to do it.

Can I combine MHDC assistance with a seller-paid rate buydown?

Often, yes: MHDC cash assistance can cover your down payment while a seller concession pays for a rate buydown. MHDC requires written approval for buydowns on First Place loans, so have your MHDC lender confirm before you make an offer; lender fees can also trim the 4%. On a $375K home with a 3% seller concession, cash to close can drop from about $30,000 to about $12,803.

How These Numbers Are Calculated

• Interest rate: 7% on a 30-year fixed loan, in line with the market as of October 2, 2026. Your rate depends on credit, loan type and the market on the day you lock.
• Property tax: 1.12% of the price for the budget range and payment table (common in St. Louis County); the area table shows each ZIP’s rate.
• Insurance: about 1% of the home’s price per year. Missouri premiums vary widely — get quotes early.
• Mortgage insurance: FHA 0.55% per year plus 1.75% upfront (financed); conventional PMI estimated at 0.60% with 5% down and 0.40% with 10% down.
• Limits: comfortable = total housing payment at 28% of gross income; lender maximum = 43% total debt-to-income, minus the other debts stated.
• Closing costs: estimated at 3% of the price.
• MHDC + buydown scenario: MHDC cash assistance at 4% of the base loan; MHDC rate assumed at the same 7% (conservative); 3% seller concession; 2-1 buydown cost = the payment difference over two years; permanent buydown at roughly 0.25% per discount point (pricing varies daily); optional lender origination fee up to 1% of the loan; 2026 St. Louis MHDC income and purchase-price limits.
• Area data: median sale price, days on market and first-weekend sale rate from 7,006 residential sales, 2025–2026, MARIS MLS.

The Bottom Line on $120K in St. Louis

On $120,000, plan around $327K, with approval possible up to $426K. That buys comfortably in St. Charles County and South County and reaches Ballwin and Kirkwood at the top. If you stretch, do it for a reason you can name — and run the comfortable alternative first.

Other incomes: $50K · $60K · $70K · $80K · $100K · $150K · $200K · Income needed by price

George Kindler

Marine Corps Veteran • Licensed Missouri Agent • 13 Years • 250+ Transactions

I work with first-time buyers making $50K-$100K every week. I know what you can actually afford, what neighborhoods fit your budget, and how to get you in a house without being house-poor. Let's talk.

📞 314.435.1087 Send Email