🏠 Mortgage Payment Calculator

"It's Not Rocket Science. It's Math."

A comprehensive mortgage calculator built with Streamlit that helps users calculate mortgage payments, compare refinance scenarios, and analyze the financial impact of different loan options.

✨ Features

📊 Current Loan Analysis

• Calculate monthly payments, interest, and remaining balance
• Track payments made and interest paid to date
• Highlight key metrics (balance remaining, interest remaining)

🔄 Refinance Comparison

• Compare current loan with refinance options
• Use current balance remaining as base loan amount
• 0.125% (1/8 point) interest rate increments
• Flexible loan terms (15, 20, 25, 30 years)

💰 Closing Costs Analysis

• Add closing costs to loan or pay out of pocket
• Show minimal impact on monthly payments
• Break-even analysis (time to recoup costs)
• Cost comparison between payment options

📈 Savings Analysis

• Monthly payment savings/increases
• Total interest impact (accurate comparison)
• Annual savings calculations
• Color-coded results (green for savings, red for increases)

📥 Export & Reporting

• Download comprehensive calculation reports
• Professional formatting with all calculations
• Timestamped files for easy organization

🚀 Getting Started

Prerequisites

• Python 3.7+
• Streamlit

Installation

1. Clone the repository:

   git clone https://github.com/yourusername/mortgage-calculator.git
   cd mortgage-calculator

2. Install dependencies:

   pip install -r requirements.txt

3. Run the application:

   streamlit run mortgage_app.py

4. Open in browser:

   • Navigate to http://localhost:8501

📋 Usage

Step 1: Current Loan Details

• Enter loan amount, interest rate, start date, and term
• Click "Calculate Current Loan" to see results

Step 2: Refinance Comparison

• Enter new interest rate and loan term
• Set closing costs (default: $5,000)
• Choose to roll costs into loan or pay out of pocket
• Click "Compare Refinance" to see analysis

Step 3: Review Results

• Compare current vs. refinance scenarios
• Review savings analysis and break-even calculations
• Download full report for sharing

🎯 Key Calculations

Accurate Interest Comparison

• Compares remaining interest on current loan vs. total interest on new loan
• Shows true financial impact of refinancing
• Color-coded results for easy interpretation

Break-Even Analysis

• Calculates time to recoup closing costs
• Provides recommendations based on timeline
• Shows minimal monthly impact of rolling in costs

📁 Project Structure

mortgage-calculator/
├── mortgage_app.py          # Main Streamlit application
├── Payment_calc.py          # Core mortgage calculation functions
├── requirements.txt         # Python dependencies
└── README.md               # Project documentation

🔧 Technical Details

Mortgage Calculations

• Standard mortgage payment formula
• Accurate amortization calculations
• Proper balance remaining calculations
• Interest paid to date tracking

Refinance Logic

• Uses current balance remaining as base loan amount
• Accounts for closing costs in loan amount
• Compares apples-to-apples interest calculations

📞 Contact

Have questions? Want to leverage the equity in your property and take cash out?

📧 Email: arallo@rhfny.com

📄 License

This project is open source and available under the MIT License.

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Built with ❤️ using Streamlit