Mortgage Affordability Calculator
Determine how much house you can afford based on your income, debts, and DTI ratios. Calculates max purchase price using front-end and back-end debt-to-income limits.
Inputs
Results
- Principal & Interest: $1,579
- Property Tax: $372
- Home Insurance: $150
- HOA: $0
- Total Housing: $2,101
- Other Debts: $500
- Total Obligations: $2,601
- Front-end (housing only): 26.26% (max: 28%)
- Back-end (all debts): 32.51% (max: 36%)
Tip: Conventional loans typically require 28% front-end and 36% back-end DTI. FHA allows up to 43% back-end.
When to Use This Calculator
Use this calculator before you start house hunting to understand your realistic price range. It prevents wasted time looking at homes you can't qualify for and helps you understand how your income, debts, and down payment interact to determine your maximum purchase price.
How It Works
This calculator uses standard lender qualification formulas based on debt-to-income (DTI) ratios. It checks both front-end DTI (housing costs only) and back-end DTI (all debts combined) to find the more restrictive limit. It factors in property taxes, insurance, and PMI if your down payment is below 20%.
Key Terms
How to Use This Mortgage Affordability Calculator (Mini Guide)
Determine how much house you can afford based on your income, existing debts, and lender DTI (debt-to-income) limits — so you don't waste time looking at homes outside your budget.
What this calculator determines
It calculates the maximum home price you qualify for based on your gross monthly income and total monthly debt payments.
Uses front-end DTI (housing only) and back-end DTI (all debts) to match real lender requirements.
Critical inputs to get right
Gross income: use your actual monthly gross (before taxes), not net.
Monthly debts: include car loans, student loans, credit cards, personal loans — anything on your credit report.
DTI limits: conventional loans typically use 28/36, FHA allows up to 43% back-end.
Property tax rate: this varies hugely by location and significantly impacts affordability.
How to interpret results
Max home price is what you qualify for — not necessarily what's comfortable.
If you have high existing debts, back-end DTI will be your limiting factor.
PMI kicks in if down payment is less than 20% — this reduces your buying power.
Next steps
Get pre-approved with a real lender to confirm these numbers.
Consider budgeting for 80% of max — gives you breathing room for life.
Use the Rent vs Buy calculator to see if monthly payments fit your lifestyle.
Try with Local Assumptions
Select a city to pre-fill the calculator with local market defaults.