Official User Manual

Welcome to the comprehensive guide for using the Mortgage Calculator suite. Our platform offers three distinct tools designed to answer different financial questions. This manual explains the features and inputs for each one.

1. Mortgage Payment Calculator

The default tool designed to answer: "How much will this house cost me every month?"

Core Inputs

• Loan Type: Select from Conventional, FHA, VA, or USDA. Changing this automatically adjusts the down payment rules and insurance calculations (like PMI or MIP).
• Home Price: The total listing price of the property.
• Down Payment: You can toggle between a dollar amount ($) and percentage (%). The tool will auto-calculate the other value.
• Credit Score: Selecting a score range helps estimation but is optional. It mainly affects the default interest rate suggestion.

Taxes, Insurance & PMI

To provide a realistic "PITI" estimate, you can customize:

• Property Tax: Enter a manual percentage or use the "State Selector" (pin icon) to apply the average rate for any US state.
• Home Insurance: An annual percentage estimate for hazard insurance.
• HOA Fees: A monthly fixed cost for Homeowners Association dues.

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2. Home Affordability Calculator

Designed to answer: "How much house can I afford on my salary?" This tool works in reverse, starting with your income to find a maximum home price.

Key Inputs

• Gross Annual Income: Your total household income before taxes.
• Monthly Debts: The sum of all minimum monthly payments (car loans, student loans, credit cards). Do not include rent or utilities.
• DTI Slider: The "Debt-to-Income" ratio slider is the most critical control. It determines the maximum percentage of your gross income that can be used for debt.

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3. Refinance Calculator

Designed to answer: "Does it make financial sense to replace my current mortgage?"

Three Modes

1. Lower Payment: Focuses on reducing your monthly obligation. Calculates "Monthly Savings" and "Break-Even Point" (time to recover closing costs).
2. Pay Off Faster: Focuses on shortening the term (e.g., 30 years to 15 years). Calculates "Total Interest Saved" over the life of the loan.
3. Get Cash Out: Calculates how much equity you can withdraw while keeping a specific Loan-to-Value (LTV) ratio.

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4. Advanced Features

Comparison Mode

On the main Payment Calculator, clicking the "Compare" button freezes your current scenario ("Scenario A") and opens a second set of inputs ("Scenario B"). This allows side-by-side analysis of:

• Two different interest rates.
• 15-year vs. 30-year terms.
• FHA vs. Conventional loans.

Amortization Views

The results section offers two ways to visualize your loan payoff:

• Chart View: A bar chart showing the ratio of Principal vs. Interest for each year.
• Table View: A detailed, month-by-month spreadsheet of payments, balances, and accrued interest.