A home affordability calculator estimates the home price your income, monthly debts, and down payment can support.[S3] It uses the 28/36 rule of thumb, which keeps your housing payment under 28% of gross income and all your debt under 36%, plus a 30-year fixed loan. That is a cautious target, not a lender cap: Fannie Mae sets no housing-only limit and allows total debt up to 50% through its automated underwriting.[S1] Closing costs of 2-5% reduce what your down payment covers. It is free, with no signup.
How Much House Can You Afford?
Enter your income, monthly debts, and down payment. This estimates the home price the conservative 28/36 debt-to-income rule supports, and the monthly payment that comes with it. If you house-hack, a second unit’s rent changes this math in your favor, more on that below.
Your numbers
[S2]What you can afford
This uses the 28/36 rule of thumb and a 30-year fixed loan; it is an estimate, not a preapproval. Conventional loans through automated underwriting (Fannie Mae allows up to 50% total debt), FHA loans and compensating factors (strong credit, cash reserves) often allow higher ratios, and closing costs of 2–5% reduce what your down payment covers. Get a real preapproval before you shop.
Related free tools: debt-to-income calculator · house hacking calculator · down payment roadmap · rent vs. buy
How the second unit’s rent changes this math: how much house you can afford when you house hack.
Estimate only. This is a planning tool, not a quote, an appraisal, or financial advice. Every result reflects the figures you enter, so change an input and the answer changes. Confirm the numbers with a lender, an agent, or your own research before you act on them.
That price assumes you carry the whole payment yourself.
the house hacking calculator. A second unit changes what you can afford, and lenders count part of the expected rent.
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Related reading
- How Much Should You Save Before Buying a House? The Full Number
- How to Afford a House on One Income
- How Much Can You Make House Hacking? My Actual Numbers
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Sources
- [S1] Fannie Mae Selling Guide, read 24 September 2026: “For manually underwritten loans, Fannie Mae's maximum total DTI ratio is 36% of the borrower's stable monthly income." "For loan casefiles underwritten through DU, the maximum allowable DTI ratio is 50%." (The page sets no separate housing-expense ratio.)” selling-guide.fanniemae.com.
- [S2] Fannie Mae Selling Guide, B3-6-03 (12/16/2020), read 24 September 2026: “Monthly housing expense is the sum of the following and is referred to as PITIA for the subject property: principal and interest (P&I); property, flood, and mortgage insurance premiums (as applicable); real estate taxes; ...” selling-guide.fanniemae.com.
- [S3] Van to Vault, read 24 September 2026: “Fannie Mae's Selling Guide caps manually underwritten loans at 36% total, allows up to 45% when the borrower meets credit score and reserve requirements, and allows up to 50% for loans run through Desktop Underwriter.” vantovault.com.