Percentage to Odds Converter - Chrome Extension

A Chrome extension that automatically converts percentages to sportsbook odds on web pages. Supports both American and European (decimal) odds formats.

Features

• 🔄 Automatic Conversion: Automatically finds and converts percentages to odds on any webpage
• 🇺🇸 American Odds: Display odds in American format (e.g., +150, -200)
• 🇪🇺 European Odds: Display odds in European/decimal format (e.g., 2.50, 1.50)
• 🎛️ Toggle Control: Enable/disable conversion with a simple toggle

Installation

Step 1: Load the Extension

1. Open Google Chrome
2. Navigate to chrome://extensions/
3. Enable Developer mode (toggle in the top-right corner)
4. Click Load unpacked
5. Select the percent-to-odds folder containing the extension files
6. The extension should now appear in your extensions list

Step 2: Use the Extension

1. Click the extension icon in the Chrome toolbar
2. Toggle the conversion on/off as needed
3. Select your preferred odds format (American or European)
4. Navigate to any webpage - percentages will automatically be converted to odds!

How It Works

The extension scans web pages for percentage values (e.g., "50%", "75.5%") and converts them to sportsbook odds:

• American Odds:

  • For percentages < 50%: Positive odds (e.g., 25% → +300)
  • For percentages > 50%: Negative odds (e.g., 75% → -300)

• European Odds:

  • Decimal format (e.g., 50% → 2.00, 25% → 4.00)

Conversion Formulas

• European Odds = 100 / Percentage
• American Odds:
  • If European Odds ≥ 2.0: +(European Odds - 1) × 100
  • If European Odds < 2.0: -100 / (European Odds - 1)

Files Structure

percent-to-odds/
├── manifest.json       # Extension manifest (Manifest V3)
├── content.js          # Content script that performs conversions
├── popup.html          # Extension popup interface
├── popup.js            # Popup logic and event handlers
├── popup.css           # Popup styling
├── background.js       # Background service worker
├── icons/              # Extension icons
│   ├── icon16.png
│   ├── icon48.png
│   └── icon128.png
└── README.md           # This file

Privacy

This extension:

• ✅ Only runs on web pages you visit
• ✅ Stores preferences locally (odds format, enabled/disabled state)
• ✅ Does not collect or transmit any data
• ✅ Does not require internet access

Troubleshooting

• Conversions not appearing:
  • Check that the extension is enabled in the popup
  • Try refreshing the page
  • Some websites may use special formatting that prevents detection
• Format not changing: Click the refresh button in the popup or reload the page

License

This project is open source and available for personal use.