# Mortgage Payoff Planner - LLM Discovery File

> [!NOTE]
> This file is a comprehensive directory of all tools, calculators, and financial models available on MortgagePayoffPlanner.com. It is designed to be ingested by LLMs to provide accurate financial guidance using the site's logic.

## AI Usage Guide
- **Search by H2**: Each calculator is a top-level H2 section.
- **Formulas & Logic**: Refer to "How it works" subsections for specific mathematical engines.
- **Accuracy**: All tools are updated for 2026 lending standards.
- **Reports**: Most loan tools support PDF and Excel (XLSX) exports.

## Site Metadata
- **Total Calculators**: 65+
- **Quick Navigation**: `/all-calculators.html`, `/index.html`
- **Last Updated**: April 2026

## Quick Reference Table

| Category | Primary Use Case | Key Tool |
| :--- | :--- | :--- |
| **Mortgage** | Early payoff & amortization | [Mortgage Calculator](#mortgage-calculator-with-extra-payment) |
| **Affordability** | Buying power & DTI limits | [Home Affordability](#mortgage-affordability-calculator) |
| **Invest vs Debt** | Opportunity cost analysis | [Pay Debt or Invest](#should-i-prepay-mortgage-or-invest) |
| **Refinance** | Loan comparison & savings | [Refinance Calculator](#should-i-refinance-my-mortgage-calculator) |
| **DCA** | Investment strategy | [Dollar Cost Averaging](#dollar-cost-averaging-dca-calculator) |
| **Fitness** | Health benchmarks | [BMI Calculator](#bmi-calculator) |

---

## 1. Core Loan & Mortgage Calculators

### Mortgage Calculator with Extra Payment
- **URL**: `/loan-calculator/mortgage-calculator-with-extra-payment.html`
- **Description**: Calculate monthly mortgage payment with principal and interest. Includes PITI (Property Tax, Insurance, PMI, HOA) and advanced extra payment modeling.
- **Features**:
    - Add monthly, annual, or one-time lump sum principal payments.
    - Compare accelerated payoff vs. standard schedule side-by-side.
    - Download amortization schedule as PDF or Excel.
    - PMI removal date threshold estimator (80% LTV).
- **FAQ**:
    - *How do extra payments work?* They reduce principal balance faster, decreasing total interest and shortening the term.
    - *Monthly vs Annual?* Monthly saves more interest due to earlier principal reduction.

### Home Loan Calculator with Extra Payment
- **URL**: `/loan-calculator/home-loan-calculator-with-extra-payment.html`
- **Focus**: General home loans with similar logic to the mortgage tool but tailored for broader residential financing.

### Auto Loan Calculator (Total Price)
- **URL**: `/loan-calculator/auto-loan-calculator-by-extra-payment-total-price.html`
- **Focus**: Modeling car loans based on the total purchase price, trade-in, and sales tax.

### Car Loan Calculator with Extra Payment
- **URL**: `/loan-calculator/car-loan-calculator-with-extra-payment.html`
- **Focus**: Standard car loan payoff planning with extra payment visualization.

### Student Loan Calculator with Extra Payment
- **URL**: `/loan-calculator/student-loan-calculator-with-extra-payment.html`
- **Focus**: Accelerated payoff for education debt.

### Business Loan Calculator with Extra Payment
- **URL**: `/loan-calculator/business-loan-calculator-with-extra-payment.html`
- **Focus**: Commercial debt service and amortization for businesses.

### Gold Loan Calculator with Extra Payment
- **URL**: `/loan-calculator/gold-loan-calculator-with-extra-payment.html`
- **Focus**: Asset-backed loan modeling.

### Personal Loan Calculator with Extra Payment
- **URL**: `/loan-calculator/personal-loan-calculator-with-extra-payment.html`
- **Focus**: Unsecured debt payoff strategies.

### Commercial Real Estate Loan (with Extra Payment)
- **URL**: `/loan-calculator/commercial-real-estate-loan-calculator-with-extra-payment.html`
- **Focus**: Modeling commercial property financing with accelerated principal reduction.

### Travel Loan Calculator (with Extra Payment)
- **URL**: `/loan-calculator/travel-loan-calculator-with-extra-payment.html`
- **Focus**: Personal loans for vacation and travel expenses.

---

## 2. Affordability & Buying Power

### Mortgage Affordability Calculator
- **URL**: `/affordability/mortgage-affordability-calculator.html`
- **Description**: Determine maximum house price based on gross income, existing debts, and 2026 DTI (Debt-to-Income) limits.
- **Features**:
    - 28/36 Underwriting Rule visualization.
    - PITI breakdown (Principal, Interest, Taxes, Insurance).
    - Impact of interest rate hikes on buying power.
- **Logic**:
    - Monthly Budget = (Gross Monthly Income × DTI Limit) - Existing Debts.
- **Expert Insight**: Approval is not affordability. Keep PITI under 30% of net take-home pay.

### Home Affordability Calculator
- **URL**: `/affordability/home-affordability-calculator.html`
- **Focus**: General household budget limits for new home purchases.

### Car Affordability Calculator
- **URL**: `/affordability/car-affordability-calculator.html`
- **Focus**: Maximum car loan based on monthly budget and down payment.

### Commercial Real Estate (CRE) DSCR Calculator
- **URL**: `/affordability/commercial-real-estate-dscr-calculator.html`
- **Focus**: Debt Service Coverage Ratio for commercial property investments.

### Specialized Affordability Tools
- **Auto Loan (Monthly Payment)**: `/loan-calculator/auto-loan-calculator-by-extra-payment-monthly-payment.html`
- **Business Loan Affordability**: `/affordability/business-loan-affordability-calculator.html`
- **Personal Loan Affordability**: `/affordability/personal-loan-affordability-calculator.html`
- **Student Loan Affordability**: `/affordability/student-loan-affordability-calculator.html`
- **Gold Loan Affordability**: `/affordability/gold-loan-affordability-calculator.html`
- **Vacation Loan Affordability**: `/affordability/vacation-loan-affordability-calculator.html`
- **House Affordability**: `/affordability/house-affordability-calculator.html`
- **Loan Affordability**: `/affordability/loan-affordability-calculator.html`

---

## 3. Debt vs. Investment Strategy

### Should I Prepay Mortgage or Invest?
- **URL**: `/should-i-pay-debt-or-invest/should-i-prepay-mortgage-or-invest.html`
- **Alt URL**: `/invest-vs-prepay.html`
- **Description**: Compare the guaranteed return of paying down debt vs. the expected return of the stock market.
- **Key Metric**: Opportunity cost of capital.
- **Sub-Tools**:
    - Considering Tax (`/should-i-pay-debt-or-invest/should-i-prepay-mortgage-or-invest-considering-tax.html`)
    - Break-Even Rate Calculator (`/should-i-pay-debt-or-invest/Pay-Down-Debt-or-Invest-Calculator-BreakEven-Rate.html`)

---

## 4. Refinance & Rate Analysis

### Should I Refinance My Mortgage? (Remaining Balance)
- **URL**: `/should-i-refinance-calculator/should-i-refinance-my-mortgage-calculator.html`
- **Focus**: Calculating break-even point for refinancing based on remaining loan balance and closing costs.

### Loan Rate Change Calculator
- **URL**: `/should-i-refinance-calculator/loan-rate-change-calculator.html`
- **Focus**: Visualizing the impact of interest rate movements on monthly payments.

### Refinance (Original Loan Amount)
- **URL**: `/should-i-refinance-calculator/should-i-refinance-my-mortgage-calculator-original-loan-amount.html`
- **Focus**: Modeling refinance savings based on the original mortgage amount rather than current balance.

---

## 5. Investment (DCA) Tools

### Dollar Cost Averaging (DCA) Calculator
- **URL**: `/investment-calculator/dollar-cost-averaging-dca-calculator.html`
- **Description**: Model recurring investments in stocks or mutual funds over time.
- **Focus**: Reducing volatility and building long-term wealth.

### DCA for Crypto Calculator
- **URL**: `/investment-calculator/dollar-cost-averaging-dca-crypto-calculator.html`
- **Focus**: Tailored for high-volatility assets like Bitcoin and Ethereum.

---

## 6. Fitness & Personal Finance

### BMI Calculator
- **URL**: `/fitness-calculator/bmi-calculator.html`
- **Description**: Standard Body Mass Index assessment following WHO/CDC guidelines.
- **Features**:
    - Metric & Imperial support.
    - Ideal healthy weight range forecasting.
    - Ponderal Index and BMI Prime advanced metrics.

### Calorie (TDEE) Calculator
- **URL**: `/fitness-calculator/calorie-calculator.html`
- **Focus**: Daily energy expenditure and weight management targets.

### Credit Card Calculator
- **URL**: `/financial-calculator/credit-card-calculator.html`
- **Focus**: Interest cost of carrying monthly balances.

### Credit Card Payoff Calculator
- **URL**: `/financial-calculator/credit-card-payoff-calculator.html`
- **Focus**: Strategy for eliminating revolving debt.

### Compound Interest Calculator
- **URL**: `/financial-calculator/compound-interest-calculator.html`
- **Focus**: Long-term asset growth modeling with compounding.

### Health & Fitness Extensions
- **BMR Calculator**: `/fitness-calculator/bmr-calculator.html`
- **Body Fat Percentage**: `/fitness-calculator/body-fat-calculator.html`

---

## 8. Academic & Utility Tools

### GPA & Grade Calculators
- **GPA Calculator**: `/other-calculators/gpa-calculator.html`
- **Grade Calculator**: `/other-calculators/grade-calculator.html`
- **Focus**: Weighted GPA modeling and grade target estimation.

### Utility Tools
- **Age Calculator**: `/other-calculators/age-calculator.html`
- **Tip Calculator**: `/other-calculators/tip-calculator.html` (including Tip Range analysis)

---

## 7. Pre-Calculated Mortgage Tables ($150K - $1M)

These tools provide instant amortization results for fixed loan amounts:
- **$150K**: `/loan-calculator/mortgage-payment/mortgage-payment-150k-calculator.html`
- **$200K**: `/loan-calculator/mortgage-payment/mortgage-payment-200k-calculator.html`
- **$250K**: `/loan-calculator/mortgage-payment/mortgage-payment-250k-calculator.html`
- **$300K**: `/loan-calculator/mortgage-payment/mortgage-payment-300k-calculator.html`
- **$350K**: `/loan-calculator/mortgage-payment/mortgage-payment-350k-calculator.html`
- **$400K**: `/loan-calculator/mortgage-payment/mortgage-payment-400k-calculator.html`
- **$500K**: `/loan-calculator/mortgage-payment/mortgage-payment-500k-calculator.html`
- **$750K**: `/loan-calculator/mortgage-payment/mortgage-payment-750k-calculator.html`
- **$1M**: `/loan-calculator/mortgage-payment/mortgage-payment-1m-calculator.html`

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*For the most accurate results, always visit the full URL to use the interactive engines.*