Finance Calc App

US Home affordability calculator

Work out the maximum home price you can comfortably afford using the 28/36 DTI rule.

By Mitch Duncan Last reviewed Methodology

Your finances

Loan & costs

Max home price
$366,928.99
Max loan
$306,928.99
Est. monthly payment
$2,240.00
Limit set by
front-end DTI (28%)

The 28/36 DTI rule — what lenders check

Housing costs ≤ 28% of gross monthly income ($2,240.00/mo). All debt payments ≤ 36% ($2,880.00/mo). Lenders vary — some allow up to 43% back-end for qualified mortgages.

Want the full picture? How Much House Can I Afford? The 28/36 Rule Explained →

How home affordability is calculated (US)

US lenders apply the 28/36 rule to size the largest mortgage they'll approve:

Whichever limit binds first sets your maximum housing payment; we back out the loan at your rate and add the down payment.

Worked example

$90,000 income, $400/month existing debt, 6.5% rate, $40,000 down:

The 20% down threshold

Putting 20% down removes PMI (~0.5–1% of the loan per year) and improves your rate. Going from 10% to 20% down on a $300,000 home commonly raises affordability by $20,000–$30,000.

Common mistakes

What this doesn't cover

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Key terms

Debt-to-Income Ratio (DTI)Mortgage Pre-ApprovalDown Payment Full glossary →

Frequently asked questions

How much house can I afford on a $100,000 salary?
Using the 28/36 rule and a 6.5% rate, $100,000 of gross income supports roughly $2,330/month in housing payments (PITI). With a 20% down payment and modest existing debts, that's about $300,000–$340,000 in home price. Your exact number depends on credit, down payment size, existing debts, and current rates — enter them above for a personalised result.
What is the 28/36 rule?
The 28/36 rule is the standard underwriting guideline most lenders apply. Your total housing payment — principal, interest, property tax, insurance, plus HOA — should be no more than 28% of your gross monthly income (the front-end ratio). All debts combined, including the mortgage, should be no more than 36% (the back-end ratio).
Does down payment affect how much house I can afford?
Yes, in two ways. A larger down payment reduces the loan amount, so the monthly payment is lower — letting you qualify for a higher purchase price within the same DTI limits. It also removes private mortgage insurance once you cross 20% down, which lowers your monthly PITI by another roughly 0.5–1% of the loan amount per year.
How does student loan debt affect mortgage affordability?
Monthly student loan payments count against the 36% back-end DTI ratio, lowering the housing payment you can afford. Every $100/month of student loans removes roughly $20,000 of mortgage capacity at typical rates. Income-driven repayment plans usually count the actual minimum payment; deferred loans may still count an estimated payment depending on the lender.
Why does this calculator not factor in credit score?
Credit score affects the rate you'll be offered, not the affordability formula itself. Plug in the rate quoted to someone with your credit profile — typically tier-A rates need a 760+ FICO; sub-700 scores usually pay 0.25–0.75 percentage points more. Use that adjusted rate above to see your real affordability.

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