BGrid User Guide

BGrid is a hierarchical coordinate system that divides the entire Earth's surface into a grid of parcels. Unlike traditional latitude and longitude coordinates, BGrid uses a recursive subdivision approach where each level divides the world into exactly 2048 parcels.

This system allows you to reference any location on Earth using either:

• Numbers: Numeric identifiers (0-2047) for each parcel at each level
• BIP39 Words: Memorable words from the Bitcoin Improvement Proposal 39 wordlist
• Decimal Degrees (DD): Traditional latitude and longitude format

The hierarchical nature means each parcel can be further subdivided into 2048 smaller parcels, creating a tree-like structure that allows for progressively finer location precision.

Basic Navigation

Desktop:

• Pan: Click and drag the map to move around
• Zoom: Use mouse wheel or +/- buttons to zoom in/out
• Select: Click any grid cell to select it and view its coordinates
• Reset: Click the BGrid logo to return to the initial view (Level 0)

Mobile/Touch:

• Pan: Drag with one finger to move the map
• Zoom: Pinch with two fingers to zoom in/out
• Select: Tap any grid cell to select it
• Menu: Tap the hamburger menu (☰) to access controls

Interface Overview

The sidebar (desktop) or menu (mobile) contains:

• Language Selector: Choose your preferred language
• Display Format Buttons: Switch between Numbers, Words, or DD format
• Location Information: Shows current level and coordinates
• Grid Lines Toggle: Show or hide the grid overlay
• Coordinate Converter: Transform lat/lon to BGrid coordinates

BGrid uses a hierarchical level system where each level provides increasingly precise location references. The system starts at Level 0 (the entire Earth) and can theoretically extend to any depth.

Level Structure

Choosing the Right Level

• L1: Best for countries, large regions, or states (~625 km accuracy)
• L2: Ideal for cities, districts, or large neighborhoods (~10-20 km accuracy)
• L3: Perfect for buildings, blocks, or specific locations (~300 m accuracy)
• L4: Very precise - individual building or address level (~5-10 m accuracy)

Tip: Start with a lower level for general areas and increase precision as needed. Higher levels create exponentially more parcels and require longer coordinate strings.

BGrid supports three different coordinate display formats, each with unique advantages:

1. Numbers Format

Displays BGrid coordinates as numeric sequences separated by dashes. Each number represents the parcel ID at that level.

Best for: Computing, APIs, databases, and technical applications

2. Words Format (BIP39)

Converts numeric coordinates to memorable words from the BIP39 wordlist (2048 words total). This format is designed for human memorization and verbal communication.

Best for: Emergency services, verbal communication, memorization, and accessibility

3. Decimal Degrees (DD)

Shows the center point of the selected parcel in standard latitude and longitude format.

Best for: GPS devices, mapping software, and compatibility with existing systems

Switching Formats

Use the format selector buttons in the sidebar to switch between formats instantly. The URL will update automatically to preserve your selected format when sharing.

The built-in converter allows you to transform traditional latitude/longitude coordinates into BGrid format. This is especially useful when you have GPS coordinates and want to express them in BGrid notation.

How to Use the Converter

1. Enter Coordinates: Type latitude and longitude in decimal degrees format, separated by a comma (e.g., 40.7128, -74.0060 for New York City)
2. Select Level: Choose your desired precision level (L1, L2, L3, or L4)
3. Convert: Click the "Convert" button to process the coordinates
4. View Results: The map will center on the location and display the BGrid coordinates

Input Format Requirements

Example Coordinates to Try

• Eiffel Tower, Paris: 48.858370, 2.294481
• Statue of Liberty, NYC: 40.689249, -74.044500
• Sydney Opera House: -33.856784, 151.215297
• Taj Mahal, India: 27.175015, 78.042155
• Christ the Redeemer, Rio: -22.951916, -43.210487

Every location and view state in BGrid has a unique URL that can be shared with anyone. The URL encodes the coordinates, format, level, and zoom state, ensuring recipients see exactly what you see.

How to Share

1. Navigate or Convert: Find your desired location on the map
2. Click Share Button: Click the share icon (📤) in the header
3. Copy URL: The URL is automatically copied to your clipboard
4. Share: Paste the URL in email, messaging apps, social media, etc.

URL Structure

BGrid URLs encode location information in a readable format:

Sharing Best Practices

• Choose Format: Select Words format for verbal sharing, Numbers for technical use
• Verify Precision: Ensure the level matches your intended precision before sharing
• Test Links: Open shared URLs to verify they point to the correct location
• QR Codes: Generate QR codes from URLs for easy mobile scanning

Grid Lines Visualization

Toggle the grid overlay to see parcel boundaries at your current zoom level. Grid lines dynamically adjust as you zoom, always showing relevant divisions.

• On: Shows parcel boundaries with colored borders
• Off: Clean map view without grid overlay

Multi-Language Support

BGrid's interface is available in five languages:

• 🇺🇸 English
• 🇪🇸 Español (Spanish)
• 🇫🇷 Français (French)
• 🇧🇷 Português (Portuguese)
• 🇨🇳 中文 (Chinese)

Note: BIP39 words remain in English for consistency, but UI labels and instructions will be translated to your selected language.

Keyboard Shortcuts (Desktop)

• +/- keys: Zoom in/out
• Arrow keys: Pan the map in any direction
• Home key: Return to Level 0 view
• Escape: Close open dialogs

Mobile Optimizations

• Touch Gestures: Full support for pinch-zoom and drag navigation
• Bottom Info Bar: Quick access to coordinates without opening menu
• Collapsible Menu: Saves screen space while navigating
• Orientation Support: Works in both portrait and landscape modes

How BGrid Works

BGrid uses a recursive space subdivision algorithm that divides the Earth's surface into progressively smaller parcels:

1. Start with the entire Earth as a single polygon (Level 0)
2. At each level, divide each parcel into exactly 2048 sub-parcels
3. Each sub-parcel is numbered 0-2047
4. Coordinates form a path: Level1-Level2-Level3-...

Coordinate Precision

The precision of BGrid coordinates depends on the chosen level. Each parcel represents the center point with the following accuracy:

BIP39 Word Mapping

Each parcel number (0-2047) maps to a unique word from the BIP39 wordlist. This 1:1 mapping ensures:

• Consistent conversion between numbers and words
• No ambiguity or conflicts
• Easy verification and validation
• Compatibility with Bitcoin/crypto tools

Data & Privacy

• No Tracking: BGrid does not track user locations or behavior
• No Server Storage: All coordinates are encoded in URLs
• Open Source: Code is publicly available on GitHub
• Offline Capable: Can be hosted locally or run offline

Map Technology

BGrid uses OpenStreetMap via Leaflet.js for map rendering. This provides:

• Free, open-source mapping data
• Regularly updated geographic information
• Community-driven accuracy improvements
• No vendor lock-in

How is BGrid different from What3Words?

While both systems use words to reference locations, BGrid is fundamentally different:

• Hierarchical: BGrid uses levels that nest within each other
• Open: BGrid is open-source and can be freely implemented
• Flexible: BGrid supports numbers, words, and decimal degrees
• Scalable: BGrid precision can extend to any level needed

Can I use BGrid offline?

The BGrid calculation system works offline. However, the OpenStreetMap tiles require an internet connection. For offline use, you can host BGrid locally with cached map tiles.

Is BGrid accurate enough for navigation?

BGrid at L3 provides meter-level accuracy, suitable for most navigation needs. L4 offers centimeter precision for applications requiring extreme accuracy.

How do I convert BGrid coordinates programmatically?

The BGrid algorithm is open-source and available on GitHub. You can implement it in any programming language or use the provided JavaScript library.

Why 2048 divisions per level?

2048 (2^11) is a power of two, making calculations efficient. It also corresponds exactly to the BIP39 wordlist size, enabling perfect word mapping without gaps or overlaps.

Can parcels cross borders or water?

Yes. BGrid parcels are geometric divisions of the Earth's surface and do not consider political borders, bodies of water, or land features. They are purely mathematical.

How do I cite or attribute BGrid?

BGrid is open-source and free to use. Attribution is appreciated but not required. Link to bgrid.org or the GitHub repository when mentioning the system.

Is there an API for BGrid?

BGrid is designed to be implemented client-side without requiring a central API. All calculations can be performed locally. Check the GitHub repository for implementation libraries and examples.