🗺️ Grid Square Lookup

About Maidenhead Locator System

The Maidenhead Locator System (also called QTH Locator or Grid Square) was developed in 1980 for VHF contesting. It divides the world into a hierarchical grid of squares, making it easy to communicate location concisely.

A 6-character grid square provides approximately 5 km × 5 km precision — sufficient for most amateur radio purposes. For higher precision, 8-character grids (subdividing further) are sometimes used in microwave contests.

The grid is used for:

• Award tracking: DXCC, WAS, WAZ, and grid square awards (e.g., VUCC for VHF)
• Contesting: Grid squares are the scoring unit for VHF/UHF contests
• Propagation: Determining path geometry and grayline conditions
• Satellite tracking: Ground station locations for doppler correction

Grid Square Structure

A grid square like FN31pr breaks down as:

• F — Field: 20° longitude × 10° latitude (A–R for longitude, A–R for latitude)
• N — Field (latitude letter)
• 3 — Square: 2° longitude × 1° latitude (0–9)
• 1 — Square (latitude digit)
• p — Subsquare: 5' longitude × 2.5' latitude (a–x)
• r — Subsquare (latitude letter)