Home Affordability Calculator

Calculate how much house you can realistically afford using standard lender 28/36 Debt-to-Income rules.

Direct Summary & Rule-of-Thumb Takeaway: Home affordability is determined by mortgage underwriting guardrails: the 28/36 Debt-to-Income (DTI) rule. Housing expenses (PITI) should not exceed 28% of gross monthly income, and total debt obligations should stay below 36%.
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Affordability Limits

Maximum Affordable Home Price
$462,000
Based on 28% housing ratio limit
Max Recommended Monthly Payment
$2,566/mo
Principal, interest, tax & insurance
Max Loan Amount
$402,000
Total Debt-to-Income (DTI)
33.4%
Target is under 36% for prime rates
AI Home Buying Coach Real-time analysis

💡 Smart Money Breakdown: Key Concepts Explained in Plain English

📏 The 28/36 Underwriting Rule

Standard mortgage lending guideline: spend no more than 28% of gross income on housing costs, and no more than 36% on total debt obligations.

📊 Debt-to-Income (DTI) Ratio

The percentage of gross monthly income allocated toward recurring debt payments. Lenders require low DTI to approve prime mortgage interest rates.

📐 The 28/36 DTI Underwriting Equations

Max PITI = Gross Monthly Income * 0.28

Max Total Debts = Gross Monthly Income * 0.36

Worked Example: A household earning $110,000/yr ($9,166/mo) with $400 in monthly car debt qualifies for a maximum monthly PITI payment of $2,566, supporting a maximum home purchase price of approximately $415,000 with 10% down.

📊 2026 Homebuyer Underwriting Benchmarks

Mortgage Benchmark 2026 US Guideline Underwriting Significance
Front-End Housing DTI Limit 28% of Gross Income Maximum recommended housing expense ratio
Back-End Total Debt DTI Limit 36% (Up to 45% Flex) Includes housing + student loans + car + credit cards
Median US Existing Home Price $412,000 National benchmark home purchase price

🎯 3 Steps to Increase Buying Power Before Applying

  1. Pay Down High-Monthly-Payment Debts: Eliminating a $400 car loan or credit card payment increases your home purchasing budget by ~$60,000.
  2. Build a 20% Down Payment Reserve: Reaching 20% equity eliminates monthly PMI payments, lowering your ongoing monthly housing bill.
  3. Optimize Credit Score Above 740: Borrowers with 740+ credit scores qualify for the lowest mortgage interest rates and PMI premiums.

28/36 Debt-to-Income (DTI) Underwriting Standards

Conforming Lending Standards: Conventional mortgage underwriters follow the 28/36 DTI guideline to assess borrower debt service safety and ensure loan qualification.

Front-End DTI (≤ 28%): Total monthly housing expense (PITI + PMI + HOA) must not exceed 28% of gross monthly income.
Back-End DTI (≤ 36%–43%): Total monthly recurring debt service (housing + car + student debt + credit cards) must not exceed 36% (or 43% Qualified Mortgage cap).

Regulatory Grounding: Fannie Mae Selling Guide; CFPB Qualified Mortgage Standards (12 CFR Part 1026).

❓ Frequently Asked Questions

Q: What is the 28/36 rule for home affordability?

The 28/36 rule dictates that housing expenses (PITI) should not exceed 28% of gross monthly income, and total debt obligations should not exceed 36%.

Q: How does Debt-to-Income (DTI) ratio affect mortgage approval?

Lenders evaluate DTI to measure repayment capacity. Lower DTI ratios qualify borrowers for higher loan amounts and competitive interest rates.

Official References & Authoritative Sources:

Reviewed by Finmatrix Financial Research Team | Last Updated: September 2026