SuperCalX

House Affordability Calculator

Calculate how much house you can afford based on income, debts, and down payment. Plan your home purchase wisely.
Calculator
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Car loans, credit cards, student loans, etc.

Analysis
Interpretation of the current calculator output

Enter values to see detailed analysis and insights.

How to Use

Step-by-step instructions
  1. 1Enter your annual gross income
  2. 2Input your total monthly debts (car loans, credit cards, etc.)
  3. 3Set your down payment percentage (typically 20%)
  4. 4Add current mortgage interest rate
  5. 5Specify loan term (typically 30 years)
  6. 6Review maximum affordable house price

House Affordability Formula

Uses the 28/36 rule: housing costs shouldn't exceed 28% of gross income, and total debt shouldn't exceed 36%.
Max Monthly Payment = min(Income × 28%, Income × 36% - Debts) Max House Price = Loan Amount ÷ (1 - Down Payment %)

Variables:

28% RuleMax housing payment as % of gross income
36% RuleMax total debt payments as % of gross income
Loan AmountCalculated from max monthly payment
Down PaymentUpfront payment as % of house price

Example

Home Buyer Example

Inputs:

Gross Income:$80,000/year
Monthly Debts:$500
Down Payment:20%
Interest Rate:6.5%
Loan Term:30 years

Steps:

  1. 1.Max housing payment = $80,000 × 28% ÷ 12 = $1,867
  2. 2.Max total debt = $80,000 × 36% ÷ 12 = $2,400
  3. 3.After debts: $2,400 - $500 = $1,900 (take minimum)
  4. 4.Affordable loan at 6.5%/30yr = ~$298,000
  5. 5.With 20% down: $298,000 ÷ 0.8 = $372,500 house
Result:
Can afford ~$372,500 house with $74,500 down payment

Frequently Asked Questions

What is the 28/36 rule?

28%: Housing costs (mortgage, taxes, insurance) should not exceed 28% of gross monthly income. 36%: Total debt payments (housing + other debts) should not exceed 36% of gross income.

How much down payment should I make?

20% avoids PMI (private mortgage insurance). Less is possible but costs more monthly. More reduces loan amount and interest. FHA loans allow as low as 3.5%.

What other costs should I budget for?

Beyond mortgage: property taxes (1-2% of home value annually), homeowners insurance ($1,000-3,000/year), HOA fees, maintenance (1% of home value/year), utilities, and closing costs (2-5% of price).