Home Affordability Calculator

Home Affordability is evaluated from Monthly Gross Income, Other Monthly Debt Payments and Down Payment. The calculation reports Maximum Home Price, Maximum Loan Amount and Est. Monthly Payment.

Results

Thanks — we’ve logged this for review.

About the Home Affordability Calculator

Home Affordability is treated here as a quantitative relation between Monthly Gross Income, Other Monthly Debt Payments, Down Payment and Mortgage Interest Rate and Maximum Home Price, Maximum Loan Amount and Est. Monthly Payment.

The calculator uses a custom php logic configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
Step 1: Maximum PITI = Monthly Income x 0.28 (front-end limit)
Step 2: Maximum PITI from back-end = Monthly Income x 0.36 - Other Debts
Step 3: Maximum PITI = min(Step 1, Step 2)
Step 4: Maximum P&I = Maximum PITI - Property Tax/month - Insurance/month
Step 5: Max Loan = P&I / [r x (1+r)ⁿ / ((1+r)ⁿ - 1)]
Step 6: Max Home Price = Max Loan + Down Payment
Where r = monthly mortgage rate, n = loan term months

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

Step 1: Maximum PITI = Monthly Income x 0.28 (front-end limit)
Step 2: Maximum PITI from back-end = Monthly Income x 0.36 - Other Debts
Step 3: Maximum PITI = min(Step 1, Step 2)
Step 4: Maximum P&I = Maximum PITI - Property Tax/month - Insurance/month
Step 5: Max Loan = P&I / [r x (1+r)ⁿ / ((1+r)ⁿ - 1)]
Step 6: Max Home Price = Max Loan + Down Payment
Where r = monthly mortgage rate, n = loan term months

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: Dual Income Couple — Suburban Home

Inputs

monthly_gross_income: 12000 monthly_debts: 600 down_payment: 80000 annual_rate: 6.75 loan_term_years: 30 property_tax_rate: 1.2 monthly_insurance: 150
Maximum Home Price: $546,205. Maximum Loan Amount: $466,205. Est. Monthly Payment: $3,720

With Monthly Gross Income = 12,000, Other Monthly Debt Payments = 600, Down Payment = 80,000 and Mortgage Interest Rate = 6.75 as the stated inputs, the result is Maximum Home Price = $546,205, Maximum Loan Amount = $466,205 and Est. Monthly Payment = $3,720. Each value corresponds to the declared output fields.

Example 2: Single Income — First-Time Buyer

Inputs

monthly_gross_income: 6500 monthly_debts: 350 down_payment: 25000 annual_rate: 7 loan_term_years: 30 property_tax_rate: 1 monthly_insurance: 120
Maximum Home Price: $272,005. Maximum Loan Amount: $247,005. Est. Monthly Payment: $1,990

With Monthly Gross Income = 6,500, Other Monthly Debt Payments = 350, Down Payment = 25,000 and Mortgage Interest Rate = 7 as the stated inputs, the result is Maximum Home Price = $272,005, Maximum Loan Amount = $247,005 and Est. Monthly Payment = $1,990. Each value corresponds to the declared output fields.

Example 3: High Income — 15-Year Mortgage

Inputs

monthly_gross_income: 18000 monthly_debts: 1200 down_payment: 150000 annual_rate: 6.25 loan_term_years: 15 property_tax_rate: 1.5 monthly_insurance: 200
Maximum Home Price: $648,003. Maximum Loan Amount: $498,003. Est. Monthly Payment: $5,280

With Monthly Gross Income = 18,000, Other Monthly Debt Payments = 1,200, Down Payment = 150,000 and Mortgage Interest Rate = 6.25 as the stated inputs, the result is Maximum Home Price = $648,003, Maximum Loan Amount = $498,003 and Est. Monthly Payment = $5,280. Each value corresponds to the declared output fields.

Example 4: Debt-Heavy Borrower — Limited Buying Power

Inputs

monthly_gross_income: 8000 monthly_debts: 1800 down_payment: 30000 annual_rate: 7 loan_term_years: 30 property_tax_rate: 1.1 monthly_insurance: 140
Maximum Home Price: $150,547. Maximum Loan Amount: $120,547. Est. Monthly Payment: $1,080

With Monthly Gross Income = 8,000, Other Monthly Debt Payments = 1,800, Down Payment = 30,000 and Mortgage Interest Rate = 7 as the stated inputs, the result is Maximum Home Price = $150,547, Maximum Loan Amount = $120,547 and Est. Monthly Payment = $1,080. Each value corresponds to the declared output fields.

Common Use Cases

  • Find the maximum home price you can afford
  • Understand how your debts limit buying power
  • Set a realistic home buying budget before house hunting