$100,000 is the anchor income for home affordability searches — the median aspiration for a first serious home purchase in the U.S. At that income, with $500 a month in other debts and $40,000 down, the math above works out to roughly $320,000 in max home price, with a $1,774 principal-and-interest payment and about $140 a month in PMI layered on top.
That PMI line is the detail most "how much house" rules of thumb skip. At $40,000 down on a $320,000 home, you're at about 87.5% loan-to-value — solidly above the 80% line where private mortgage insurance kicks in. It's not a rounding error: it's real monthly cost, and it changes depending on exactly how much you put down.
The down-payment decision that actually moves your number
On $100k income, the single biggest lever isn't your rate or your debts — it's whether you cross the 20%-down line. Below 20% down, PMI applies to the loan balance every month until you refinance or your equity crosses 80% naturally. At exactly 20% down, PMI disappears entirely, and in some cases that alone shifts what actually limits your price from your income to the loan-to-value boundary itself.
Run the "Put 20% down" scenario chip on the calculator above against your own numbers. If you're currently putting down 10–15%, you'll usually see PMI removed at the cost of needing more cash upfront — and depending on your income, the max price you can support might barely move, or it might jump, because the freed-up PMI budget goes straight back into what you can borrow.
Why $100k affords $320k and not a flat income multiple
A common rule of thumb says multiply income by 3 to get an affordable price — that would put a $100k earner at $300,000, suspiciously close to this calculator's answer, but only by coincidence. The 3x rule doesn't account for your specific rate, tax rate, insurance cost, or debt load; it's a rough historical average that breaks down the moment your rate, taxes, or debts differ from the assumptions baked into it.
This calculator instead solves the two DTI caps directly against your real numbers: the front-end ratio (housing costs alone, capped at 28% of gross monthly income) and the back-end ratio (housing plus all other debt, capped at 36%). At $100k income with $500 in other debts, the front-end cap binds first — meaning paying off debt wouldn't raise your number, but a lower rate or bigger down payment would.
Frequently asked questions
How much house can I afford making $100,000 a year?
With typical debts (around $500/mo) and a 10–15% down payment at current rates, expect a max home price in the $300,000–$330,000 range. Your exact number depends heavily on your down payment size (PMI status), your rate, and your other monthly debts — run the calculator above with your real figures.
Can I afford a $500,000 house on $100k income?
Not comfortably under standard 28/36 DTI caps — a $500,000 home typically requires income in the $130,000–$150,000 range depending on your down payment and debts. On $100k, a $500,000 home would push your DTI well past standard lending caps unless you have a very large down payment or minimal other debt.
Is $100k a good salary to buy a house?
Yes, in most U.S. markets outside the highest-cost coastal metros. $100k supports a home in the $300,000–$330,000 range under standard assumptions, which covers the median home price in the large majority of U.S. metro areas as of 2026. In San Francisco, New York, or similar top-tier markets, $100k alone is tight without a large down payment.
How much should I put down on a $320,000 house?
20% ($64,000) eliminates PMI entirely. Less than that — commonly 3%, 5%, or 10% — is normal and widely available, but adds a monthly PMI cost until your equity crosses 80% of the home's value. Use the "Put 20% down" scenario above to see the exact trade-off for your own numbers.
Worked examples
Worked example 1
$100k, typical debt, 12.5% down
$100,000 income, $500/mo other debts, $40,000 down, 6.5% rate.
Max home price
$320,673
Binding constraint
front
PMI
$140/mo
$320,673 max price, $140/mo PMI at 87.5% LTV — the front-end ratio is what's binding here.
What affects the result
Down payment vs the 20% line
At $40,000 down (12.5%), PMI adds roughly $140/mo; reaching 20% down removes it entirely.
Other debts
At this income and debt level, the front-end ratio binds first — other debts below roughly $700/mo don't move the number.
More questions answered
What credit score do I need to buy a $320,000 house?
Credit score doesn't change your DTI-based max price directly, but it sets your interest rate — a lower score means a higher rate, which lowers your qualifying loan amount. Conventional loans typically want 620+; FHA allows scores as low as 500–580 with a larger down payment.
Model assumptions & disclosures
Not a pre-approval. This calculator estimates your maximum home price using standard debt-to-income (DTI) caps against the income, debts, rate, and down payment you enter. It does not verify income, assets, credit, or employment, and it is not an offer or commitment from any lender. Actual mortgage pre-approval requires full lender verification and may differ from this estimate.
DTI caps are lender-dependent. The 28/36 (conventional) and 31/43 (FHA) caps used as defaults are common industry guidelines, not universal rules. Individual lenders, loan programs, and automated underwriting systems can approve — or require — different ratios based on credit score, cash reserves, loan-to-value, and other compensating factors not modeled here.
Rate, tax, insurance, and PMI are your estimates, not live data. This calculator never fetches a current mortgage rate, your actual local property tax rate, or a real insurance quote. Defaults are reasonable national approximations — enter your own numbers, or figures a lender or insurer has actually quoted you, for an accurate result.
Credit score is not modeled. Your interest rate — which directly drives your monthly payment and therefore your DTI — depends on your credit score and the specific loan program. This calculator assumes whatever rate you enter; it does not estimate what rate you would actually qualify for.
Not financial or legal advice. This calculator provides illustrative estimates based on your inputs. It does not account for your complete financial picture, local market conditions, or individual circumstances. Consult a qualified mortgage lender, financial advisor, or housing counselor before making a home-purchase decision.