How Much Can I Borrow? Mortgage Affordability Calculator (2026)
Determining 'how much can I borrow' is the first step in home buying. We explain the 28/36 rule, income requirements for 400k mortgages, and provide an interactive borrowing power calculator.
The question "how much can I borrow" begins with income, existing debts, down payment, local ownership costs, and a quoted rate. This guide uses 28% and 36% ratios as editable planning assumptions and provides examples for several loan amounts. It does not predict lender approval.
The 28/36 Rule Explained Simply
This guide uses the 28/36 rule as two editable planning assumptions. It allocates 28% of gross income to housing and 36% to total debt, but it does not represent universal lender criteria or guarantee room for other expenses.
- Selected housing-cost ratio (28%): The example multiplies gross monthly income by 28% to produce a planning amount.
- Selected total-debt ratio (36%): The example multiplies gross monthly income by 36% and subtracts entered recurring debts.
This illustrative calculation uses the lower result from its 28% housing-cost and 36% total-debt assumptions. Actual underwriting methods and debt treatment vary by lender and loan program.
Illustrative Income by Mortgage Amount
Wondering what salary do I need for a 400k mortgage? The following table uses a 6.5% example annual interest rate, a 30-year term, a selected $250 monthly tax-and-insurance input, and the editable 28% planning ratio. The figures are scenario outputs rather than income requirements or approval thresholds.
| Loan Amount | Monthly Payment (Est.) | Illustrative Annual Income |
|---|---|---|
| $100,000 | $882 | $38,000 |
| $200,000 | $1,514 | $65,000 |
| $300,000 | $2,146 | $92,000 |
| $400,000 | $2,778 | $119,000 |
| $500,000 | $3,410 | $146,000 |
Note: These are estimates. Use our mortgage calculator to refine these numbers with your specific interest rate and local tax data. For a specific breakdown, see the $400,000 mortgage at 6.5%.
Inputs That Can Change a Lender's Calculation
Actual underwriting varies by lender and program. Common inputs include:
- Income: The income a lender accepts and how it documents that income depend on the program. This page uses gross income only for its illustrative ratios.
- Credit and debts: Credit, recurring obligations, and pricing criteria vary by lender and product. Compare written terms rather than assuming a cutoff.
- Down Payment: The more you put down, the less you borrow, which lowers your monthly payment and increases the total home price you can afford.
Can I get a $400k mortgage on a $70k salary?
At the selected 6.5% example rate, a $400,000 loan costs about $2,528 in principal and interest. On a $70,000 salary ($5,833 per month), that is about 43% of gross income before taxes, insurance, maintenance, and other costs. Use that calculation as a stress test, then compare it with your full budget and lender-specific criteria. See the $90,000 salary scenario or read how the 28/36 planning rule works.
Summary of Borrowing Power
Understanding your limit is about more than just qualifying: it's about financial health. Use our tool above to experiment with different income levels and debt scenarios. Remember that "how much the bank will give me" and "how much I should spend" are often two different numbers.