A modern, interactive mortgage amortization calculator built with React and Chakra UI. Calculate mortgage payments, view detailed amortization schedules, and compare different loan scenarios side-by-side.

This calculator is for educational and estimation purposes only. The calculations provided are approximations and should not be considered as financial advice or guarantee of actual loan terms. Actual mortgage payments may vary based on:

• Lender-specific fees and requirements
• Credit score and financial history
• Property taxes and insurance costs
• Private mortgage insurance (PMI)
• Closing costs and other charges
• Market conditions and rate changes

Always consult with qualified financial professionals, mortgage brokers, or lenders for accurate loan information and personalized financial advice before making any mortgage decisions.

• Monthly Payment Calculation: Accurate P&I calculations based on loan amount, interest rate, and term
• Complete Amortization Schedule: View every payment with principal/interest breakdown
• Extra Principal Support: Calculate savings from additional principal payments
• HOA Fee Integration: Include homeowner association fees in your calculations

• Dual Schedule Analysis: Compare two different loan scenarios simultaneously
• Pre-filled Comparison Values: Quickly modify parameters for easy comparison
• Savings Analytics: See payments avoided and interest saved with different scenarios
• Individual Schedule Management: Remove schedules independently with intuitive controls

• Payments Avoided: See how many payments you can eliminate with extra principal
• Interest Avoided: Calculate total interest savings from different payment strategies
• Total Cost Analysis: View complete loan costs across different scenarios
• Date-Aware Scheduling: Optional payment dates with month/year display

• Step-by-Step Wizard: Intuitive questionnaire interface for data entry
• Interactive Animations: Smooth transitions and hover effects
• Input Validation: Real-time feedback with visual validation states
• Responsive Design: Works seamlessly on desktop and mobile devices
• Professional Styling: Clean, modern interface with depth and visual hierarchy

• Frontend: React 18 with Vite for fast development
• UI Library: Chakra UI v3 for components and styling
• State Management: React hooks for local state
• Development: ESLint for code quality

• Node.js 18+
• npm or yarn

1. Clone the repository:

git clone https://github.com/joshuakiley/simple-amort.git
cd simple-amort

2. Install dependencies:

npm install

3. Start the development server:

npm run dev

4. Open your browser to http://localhost:5174

npm run build

The built application will be in the dist directory.

1. Enter your loan amount (e.g., $400,000)
2. Specify annual interest rate (e.g., 6.5%)
3. Set loan term in years (e.g., 30)
4. Optionally add first payment date and HOA fees
5. Add extra principal payments if desired
6. Click "Calculate Schedule" to view results

1. Complete your first schedule calculation
2. Click "Add Comparison Schedule"
3. Modify parameters for your second scenario
4. View side-by-side results with savings analysis
5. Use the red X buttons to remove individual schedules

• Monthly Payment: Using standard amortization formula
• Principal/Interest Split: Calculated for each payment period
• Extra Principal Impact: Applied to reduce remaining balance
• Payments Saved: Compares schedule length with/without extra payments
• Interest Avoided: Calculates total interest savings from payment strategies

This project was developed through a collaborative effort between human creativity and GitHub Copilot, an AI-powered coding assistant.

GitHub Copilot provided:

• Code generation and implementation suggestions
• Mathematical formula implementation for mortgage calculations
• React state management and component architecture recommendations
• Bug fixes and optimization suggestions
• Basic UI component scaffolding

Human contributions (Joshua HeKiley) included:

• Overall application design and user experience vision
• UI/UX optimization and visual refinements
• Performance tweaks and code optimization
• User workflow design and step-by-step interface
• Visual styling enhancements and design polish
• Product requirements and feature specifications
• Testing, validation, and quality assurance

This project demonstrates effective human-AI collaboration, where AI assistance accelerated development while human oversight ensured design quality, user experience, and overall product vision.

Technology Credit: GitHub Copilot by GitHub/OpenAI

MIT License - see LICENSE file for details.

Pull requests welcome! Please ensure code follows the existing style and includes appropriate documentation.