A web-based compound interest calculator that helps users calculate the growth of their investments over time.

• Calculate compound interest with various parameters
• Support for different compounding frequencies (annually, semi-annually, quarterly, monthly, daily)
• Visual representation of growth over time
• Additional contributions support
• Real-time calculations as you type

├── backend/
│   └── index.ts             # Main HTTP server (Hono)
├── frontend/
│   ├── index.html           # Main HTML template
│   ├── index.tsx            # React frontend entry point
│   └── style.css            # Custom styles
├── shared/
│   └── types.ts             # Shared TypeScript types
└── README.md

The calculator accepts the following inputs:

• Principal amount (initial investment)
• Annual interest rate (%)
• Time period (years)
• Compounding frequency
• Additional monthly contributions (optional)

The compound interest formula used:

A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]

Where:

• A = Final amount
• P = Principal amount
• r = Annual interest rate (decimal)
• n = Number of times interest compounds per year
• t = Time in years
• PMT = Additional monthly payment