House Affordability Calculator

The number a lender uses, before a lender sees you. Gross income, monthly debts, savings, rate. Max house price, implied payment, down payment needed.

Gross annual income ($)Combined if applying jointly Monthly debt payments ($)Student loans, car, minimums on cards Savings for purchase ($) Mortgage rate (%) Property tax (% of price / yr) Home insurance ($ / yr) Down payment (% of price) Loan term

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Max house price (28/36)	—
Max loan (after down)	—
Down payment	—
Housing payment cap	—
Payment at max price	—
Debt-to-income at max	—
Stretch: 28/45 price	—
Cash left after close	—

Cash left uses a 2% closing-cost allowance on the loan. Negative means the down payment does not cover closing; lenders check reserves, keep 3-6 months of payments in the bank.

How the math works

Front-end cap: housing (P&I + tax + insurance) ≤ 28% of gross monthly income. Back-end cap: housing + your debts ≤ 36%. Max housing = the smaller of the two.

Loan solve: housing = P&I + price×tax% ÷ 12 + ins ÷ 12, P&I = annuity(loan, rate, term), loan = (price − down) with PMI on loans over 80% LTV at 0.5%/yr. Solved by bisection over price.

28/45 stretch: same solve with the back-end cap at 45%, the ceiling most 2026 lenders actually run for clean files.

Cash cap: price is also capped by your savings — (savings − $2,000 reserves) ÷ (down% + 2% closing on the loan). Income capacity above what you can fund is shown as cash left, not as a price.

Numbers assume stable rate, income verified W-2, no other obligations. FHA/VA add their own insurance (MIP/funding fee, ~1.75-2.3%); not in the caps above.

Disclaimer. Pre-qualify math only, not a commitment. Underwriting uses your actual credit, verified income, and appraisal; FHA/VA/USDA programs add their own insurance costs. A lender's numbers can be higher or lower than these.

Frequently asked questions

How much house can I afford on a $100,000 salary?

Roughly a $380,000 to $420,000 home at 20% down with no other debt, using the standard 28% front-end rule and 2026 rates. With $800 of monthly student loans the same salary supports about $290,000, because the 36% back-end cap binds first.

What is the 28/36 rule?

The classic lender screen: total housing costs under 28% of gross monthly income, and all debt payments under 36%. The lower of the two caps your loan. Many lenders run 28/45 today, so this calculator reports the conservative number and the 28/45 stretch number.

Does my down payment change what I can borrow?

It changes the loan, not the income cap. More down cuts the loan and payment, and drops PMI; the 28% cap then leaves headroom for a pricier home. Under 20% down, PMI eats part of the same 28% budget.