How Much House Can I Afford? (28/36 Rule Calculator)
Calculate your maximum affordable home price based on household income, existing debt, and down payment.
Reviewed by: Marcus Vance, CFA • Quantitative Finance Review Board
Methodology: Verified Formula
Presets:
Maximum Affordable Home Price
$405,532
Max Safe Monthly Housing Budget
$2,800/mo
Max Mortgage Loan
$345,532
Based on the standard lender 28/36 qualification rule.
Scenario Comparison & Benchmark Table (House Affordability)
Compare how scaling Annual Household Income ($) affects your output (click any row to load those values into the calculator above):
| Annual Household Income ($) | Maximum Affordable Home Price | Max Safe Monthly Housing Budget | Max Mortgage Loan |
|---|---|---|---|
| 60,000 | $220,426 | $1,300/mo | $160,426 |
| 90,000 | $319,149 | $2,100/mo | $259,149 |
| 120,000 (Baseline) | $405,532 | $2,800/mo | $345,532 |
| 150,000 | $491,916 | $3,500/mo | $431,916 |
| 180,000 | $578,299 | $4,200/mo | $518,299 |
| 240,000 | $751,065 | $5,600/mo | $691,065 |
Mathematical Formula & Step-by-Step Guide
Primary mathematical equation used by this model:
Max PITI = min(GrossMo × 0.28, GrossMo × 0.36 - MonthlyDebt); Max Price = MaxLoan + DownPayment
- Configure your primary input (Annual Household Income ($), baseline set to 120,000) using either the direct numeric box or synchronized range slider.
- Adjust the remaining parameters (Existing Monthly Debts ($), Available Down Payment ($), Mortgage Interest Rate (%)) to mirror your exact scenario.
- Examine the primary output alongside the secondary breakdown metrics and the 6-tier benchmark comparison table below.
Primary Standards & References: Federal Reserve H.15 Selected Interest Rates, CFPB Regulation Z (Truth in Lending Appendix J), IRS Publication 590 & SEC Investor.gov Compounding Methodology
Financial models are for educational planning and scenario comparison only and do not constitute fiduciary investment, tax, or mortgage lending advice.
Financial models are for educational planning and scenario comparison only and do not constitute fiduciary investment, tax, or mortgage lending advice.
Frequently Asked Questions — House Affordability
What mathematical formula does the How Much House Can I Afford? (28/36 Rule Calculator) use?
This calculator implements the verified relationship: Max PITI = min(GrossMo × 0.28, GrossMo × 0.36 - MonthlyDebt); Max Price = MaxLoan + DownPayment. Each variable (Annual Household Income ($), Existing Monthly Debts ($), Available Down Payment ($), Mortgage Interest Rate (%)) is evaluated in real time using double-precision floating-point arithmetic so there is zero rounding drift across multi-step scenarios.
How does changing Annual Household Income ($) impact the final result?
Annual Household Income ($) acts as the primary driver in this model (default baseline: 120,000). Use the Reference Benchmark Table on this page to compare how scaling Annual Household Income ($) from conservative to aggressive levels changes both the primary outcome and secondary ratios.
What standards and sources back this House Affordability methodology?
Our model is audited by Marcus Vance, CFA • Quantitative Finance Review Board and calibrated against Federal Reserve H.15 Selected Interest Rates, CFPB Regulation Z (Truth in Lending Appendix J), IRS Publication 590 & SEC Investor.gov Compounding Methodology. Note: Financial models are for educational planning and scenario comparison only and do not constitute fiduciary investment, tax, or mortgage lending advice.