Propagation · Grid Map

Maidenhead Grid Map

Propagation quality overlaid on the Maidenhead grid — click any square to get its locator, or find yours automatically.

Maidenhead Grid

Propagation map

Kp: — · SFI: — · Cell colors show estimated HF propagation quality

Your grid square —

Selected click the map

Find a square

Propagation:

Excellent (SFI>150) Good (SFI>120) Moderate (SFI>90) Polar unsettled Polar storm

Reference

About the Maidenhead system

Developed in 1980 at a meeting of European VHF managers in Maidenhead, UK, this locator system is the universal language for amateur radio station positions.

Field · 2 letters

AA to RR

18 columns × 18 rows cover the globe. Each field spans 20° longitude × 10° latitude — about the size of a large country. Your field prefix identifies your broad region (FN, IO, JN…).

Square · + 2 digits

00 to 99

Each field divided into a 10×10 sub-grid. Adding two digits gives a 4-character locator (FN31) covering 2° × 1°. This is the minimum needed for VHF and HF DX exchanges.

Subsquare · + 2 letters

AA to XX

A further 24×24 subdivision gives a 6-character locator (FN31pr) placing you within about 5 km. Used for weak-signal and microwave contacts where precision matters.

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