Grid Square Converter
Convert between Maidenhead grid squares and geographic coordinates. Supports 4, 6, and 8 character precision. You can also look up the grid square for any US ZIP code.
Grid Square Precision Levels
| Characters | Example | Lon Resolution | Lat Resolution | Approx. Area |
|---|---|---|---|---|
| 4 (Field + Square) | EN53 | 2° | 1° | ~111 km × 111 km |
| 6 (Subsquare) | EN53dj | 5' | 2.5' | ~4.6 km × 4.6 km |
| 8 (Extended) | EN53dj27 | 30" | 15" | ~460 m × 460 m |
Understanding the Maidenhead Locator System
What is a grid square? The Maidenhead Locator System is a geographic coordinate encoding used by amateur radio operators worldwide. It divides the Earth's surface into a hierarchical grid of progressively smaller rectangles, each identified by an alternating sequence of letters and digits. The most common format is six characters (e.g. EN53dj), which identifies a roughly 4.6 km × 4.6 km area.
VHF/UHF contesting: Grid squares are the multiplier in ARRL VHF/UHF contests — working a station in a new grid earns bonus points. Contesting rovers drive from grid to grid to give out rare multipliers, making the grid system central to VHF contest strategy.
POTA, SOTA, and portable ops: Parks on the Air (POTA) and Summits on the Air (SOTA) activators log their grid square as part of every contact. An 8-character grid (extended precision) pins your location to within ~460 meters, which is usually sufficient for portable QTH logging.
Satellite contacts: Grid squares are required for satellite QSOs. Knowing your exact grid square helps other operators calculate antenna aiming and Doppler correction.
Tip: Use the Ham Radio Call Sign Lookup to see the grid square registered to any US call sign, and the Band Plan Checker to verify your operating privileges.
This tool was created by Ben Crittenden, an IT professional with experience in web development, systems administration, and project management.