How much house can I afford?

A common guideline is the 28/36 rule: spend no more than 28% of gross monthly income on housing costs and no more than 36% on total debt. With a $80,000 annual income, this means roughly $1,867/month on housing.

What is the debt-to-income ratio for a mortgage?

Most lenders require a debt-to-income (DTI) ratio below 43%. The front-end ratio (housing only) should ideally be below 28%. A lower DTI means better loan terms and a higher chance of approval.

How much down payment do I need?

Conventional loans typically require 3-20% down. A 20% down payment avoids Private Mortgage Insurance (PMI). FHA loans allow as little as 3.5% down with a credit score of 580 or higher.

What is PMI and how can I avoid it?

PMI (Private Mortgage Insurance) protects lenders if you default. It costs 0.5–1.5% of the loan amount annually. Avoid PMI by putting down 20% or using piggyback loans (80-10-10). PMI is automatically removed once you reach 22% equity.

What other costs should I budget for?

Beyond mortgage payments, budget for: property taxes (1–2% of home value annually), homeowners insurance ($800–2,000/year), HOA fees ($200–500/month in some areas), maintenance (1–2% of home value annually), and closing costs (2–5% of purchase price).

How does interest rate affect affordability?

A 1% rate increase on a $400,000 loan adds roughly $250/month to payments. At 6% vs 7%, the monthly difference is significant. Higher rates reduce the maximum home price you can afford. Consider rate locks when applying for mortgages.

Should I buy now or wait?

Consider: current interest rates, home price trends in your area, your savings for down payment, and job stability. If rates are high but prices are stable, waiting may help. If prices are rising rapidly, buying now may be cheaper despite higher rates. Use this calculator to model scenarios.

What credit score do I need for a mortgage?

Conventional loans typically require 620+ for approval, 740+ for best rates. FHA loans accept 580+ with 3.5% down. Higher scores mean lower interest rates — potentially saving $10,000–50,000 over the loan lifetime. Check your score before applying.

Home Affordability Calculator

Your Financial Profile

Annual Gross Income ($)

Monthly Debt Payments ($)Car loans, student loans, credit cards

Down Payment ($)

Interest Rate (%)

Loan Term

Annual Property Tax ($)

Maximum Affordable Home Price

$295,774

Max Monthly Payment

$1,867/mo

Loan Amount

$255,774

Front-End DTI

28.0%

Back-End DTI

35.5%

⚠️ Down payment is 10-20%. PMI will apply until you reach 20% equity.

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// The Rule

28 / 36

Front-end DTI ≤ 28% — Back-end DTI ≤ 36% of gross monthly income

28%

Front-End DTI

Max housing costs as % of gross monthly income

36%

Back-End DTI

All debt combined (housing + loans + cards)

20%

Down Payment

Target to avoid PMI and unlock best rates

LTV

Loan-to-Value

Below 80% LTV avoids mortgage insurance costs

Lender vs. Reality

The Bank's Number ≠ Your Number

Pre-approval figures are a ceiling, not a target. The 28/36 rule protects your financial wellbeing long after moving day. Just because a lender will approve $400k doesn't mean $400k is the right number for your life.

// How it works

Understanding Home Affordability

Lenders evaluate two debt-to-income ratios simultaneously. The front-end DTI (or housing ratio) measures only your housing costs against gross income. The back-end DTI adds all other recurring debt — car loans, student loans, credit cards — to the housing cost.

Meeting both thresholds matters because passing the front-end alone isn't enough. A buyer with $800/month in car and student loan payments has far less borrowing capacity than an identical buyer with zero other debts — even with the same income and down payment.

FHA loans allow up to 43% back-end DTI. Conventional loans typically require 36–45%. The 28/36 rule is the conservative standard — ideal for financial safety, not just loan approval.

// By market

Affordability by Region

🇺🇸 United States — DTI-Based Lending

US lenders primarily use DTI ratios. Conventional loans: 36–45% back-end. FHA loans: up to 43%. On $80k income with no debts: ~$295k at 6.5%, 30yr. Always factor property tax and HOA fees.

🇬🇧 United Kingdom — Salary Multiple Model

UK lenders use 4–4.5× annual salary as a primary multiplier, then stress-test affordability. On £50k salary: up to £225k mortgage. Deposit size heavily influences the rate offered.

🌏 AU / CA — Variable Stress Tests

Australian and Canadian lenders apply stress tests at rates 2–3% above current. This reduces maximum borrowing by 15–20% vs. face-value calculations — intentionally conservative.

// Common Questions

Frequently Asked Questions

Lenders use two DTI ratios: front-end (housing costs ≤ 28% of gross income) and back-end (all debts ≤ 36%). The lower of the two determines your maximum payment. LTV below 80% avoids PMI and unlocks better rates.

With $80k income, no other debts, 20% down, and a 6.5% rate: approximately $295k–$325k. Monthly payment stays within the 28% front-end threshold. Adding monthly debts (car, student loan) reduces this significantly.

Yes, as a benchmark — but with 2024–2025 rates, many buyers stretch to 35–40% housing costs. The rule dates from a lower-rate era. Use it as a starting point and personalise with your actual budget and financial goals.

Student loan payments count as monthly debt obligations and directly reduce your maximum back-end DTI headroom. $400/month in student loans on a $5,000/month income effectively reduces your affordable home price by $60k–$80k.

A 20% down payment eliminates PMI (0.5–1% annually), typically secures a better rate, and reduces monthly payments. On a $300k home, the total savings over 30 years compared to 10% down can exceed $40,000–$60,000.

Closing costs (2–5% of the purchase price), home inspection, PMI if applicable, homeowner's association (HOA) fees, utilities, and maintenance (budget 1–2% of home value annually). Always add these to your planning budget.

No. Maximum affordability is a ceiling, not a target. Most financial advisors recommend buying at 80–90% of your calculated maximum to preserve financial flexibility, emergency funds, and quality of life.

Each 1% rate increase reduces buying power by roughly 10–12%. At 5% you could afford $350k; at 7% that same payment only supports $290k. Locking in a lower rate — even briefly — can be worth tens of thousands in buying power.

// Methodology & References

Formula & Calculation Method

28/36 Rule (Front-end / Back-end Ratio)

Max_Housing = 0.28 × Gross_Monthly_Income;  Max_Total_Debt = 0.36 × Gross_Monthly_Income

Max_Housing — Maximum monthly housing payment (PITI: Principal + Interest + Tax + Insurance)
Max_Total_Debt — Maximum total monthly debt payments including housing

Source: Federal Reserve / CFPB Qualified Mortgage standard

Maximum Home Price

Max_Price = (Max_Housing − Tax − Insurance) / [r(1+r)^n / ((1+r)^n − 1)] + Down_Payment

r — Monthly mortgage rate
n — Loan term in months

Authoritative Sources & Standards

CFPB: Qualified Mortgage (QM) Rule under Dodd-Frank: max debt-to-income ratio of 43% (general QM) or aligned with GSE eligibility (Patch QM through 2026). → CFPB
HUD: FHA debt-to-income limits: 31% front-end housing ratio, 43% back-end total debt ratio (with compensating factors up to 50%). → HUD

Expert Insights & Research

The 28/36 rule originates from the 1970s housing market; current Fed research shows debt-to-income above 43% triples mortgage default risk (Federal Reserve Bulletin, 2022).

— Federal Reserve Mortgage Bankers Association Performance Study (2022)

First-time buyers who put down 20% pay $200–$400/month less than 5%-down buyers due to PMI elimination and lower base loan amount. Break-even on PMI removal: ~4 years on average.

— Urban Institute Housing Finance Policy Center (2024)

// Explore More