Financial Tool
House Affordability Calculator
Estimate the purchase price of a home based on debt-to-income (DTI) rules.
Income & Assets
Debts & Rates
Maximum Home Purchase Price
$343,161
Max Monthly (P&I)
$2,150
Estimated Loan
$323,161
Σ The Formula
PI = (Income × 0.36) - Debts
Real World Examples
Standard White-Collar
$85k income with $400/mo debt can afford ~$345k home at 7% with $20k down.
Aggressive DTI
Lenders sometimes allow up to 43% or 50% DTI, significantly increasing the purchase limit.
# About This Calculator
The House Affordability Calculator helps you estimate a realistic home purchase price based on the industry-standard 28/36 Rule used by mortgage underwriters.
The 28/36 Rule Explained:
- Front-End Ratio (28%): Your house payment (Principal, Interest, Taxes, Insurance) should not exceed 28% of your gross monthly income.
- Back-End Ratio (36%): Your total monthly debt payments (House + Car + Student Loans + Credit Cards) should not exceed 36% of your gross monthly income.
This calculator primarily focuses on the Back-End Ratio (Total Debt Impact) to ensure you don't become "house poor."
How To Use
- Enter your **Annual Gross Income** (before taxes).
- Enter your **Monthly Debts** (minimum payments on credit cards, car loans, etc.).
- Enter your available **Down Payment**.
- Adjust the **Interest Rate** and **DTI Limit** (Conservative: 36%, Aggressive: 43-50%).
- The result estimates your **Maximum Loan** and **Home Price**.
Frequently Asked Questions
Does this include Property Taxes and Insurance?+
This calculator estimates the 'Principal & Interest' (P&I) capacity. In the real world, your actual buying power will be slightly lower because lenders effectively deduct estimated taxes and insurance from your monthly capacity. To be safe, increase your 'Monthly Debts' input by ~$300-$500 to account for these escrows.
What is DTI?+
DTI stands for Debt-to-Income ratio. It's the percentage of your gross monthly income that goes toward paying debts. Lenders use it to measure your ability to manage monthly payments and repay the money you plan to borrow.
Can I qualify for more?+
Yes. FHA loans often allow DTI ratios up to 43% or even 50% in some cases. You can adjust the 'DTI Limit' slider (default 36%) to see how it affects your buying power, but be careful not to overstretch your budget.
How much down payment do I need?+
Traditional loans often require 20% to avoid PMI (Private Mortgage Insurance), but FHA loans allow as low as 3.5%, and VA/USDA loans can be 0%. Entering a higher down payment increases your max purchase price directly.
Is House Affordability Calculator free to use?+
Yes, House Affordability Calculator on Matheric is completely free to use. We believe in accessible education and utility for everyone.
How accurate is House Affordability Calculator?+
We use standard mathematical formulas and high-precision computing algorithms to ensure results for House Affordability Calculator are accurate for academic and professional use.