Maidenhead Grid Locator Converter
Convert latitude/longitude to a Maidenhead (QTH) grid square and back. Used by ham radio operators worldwide. Supports 4, 6, 8 and 10-character locators. Free, runs in your browser.
Lat/Long → Maidenhead
Maidenhead → Lat/Long
How Maidenhead locators work
The Maidenhead system (devised in 1980 at a VHF conference in Maidenhead, England) divides the globe into nested cells, alternating between pairs of letters and digits:
- Field (2 letters): 20° longitude × 10° latitude — e.g.
FNcovers New England and the US mid-Atlantic. - Square (2 digits): 2° × 1° —
FN30is Manhattan. - Subsquare (2 letters): 5′ × 2.5′ (~5 km) —
FN30xris Times Square. - Extended pairs (digits, then letters): each adds ~24× resolution.
FN30xr46≈ 200 m.
Frequently Asked Questions
What is a Maidenhead grid locator?
A Maidenhead locator (also called a QTH locator or grid square) is a geographic coordinate system used by amateur (ham) radio operators. It divides the Earth into a hierarchy of grid squares: two fields of 20° longitude × 10° latitude, two squares of 2° × 1°, and two subsquares of 5′ × 2.5′. A 6-character locator like FN30xr resolves to about 5 km.
Why do ham radio operators use Maidenhead?
A Maidenhead locator is short, pronounceable over the air, and easy to log. A 6-character code identifies a station to within a few kilometres — enough for "worked all states" awards, VHF contests, and satellite tracking, where lat/long pairs would be too verbose.
What resolution do longer locators give?
Each pair of characters adds another subdivision by 24 (for letters) or 10 (for digits). 4 characters ≈ 110 km, 6 characters ≈ 5 km, 8 characters ≈ 200 m, 10 characters ≈ 10 m. Most contacts use 6; high-precision work (microwave contests, balloon tracking) uses 8 or 10.
How do I find my grid square?
Enter your latitude and longitude above (or click your location on the map) and the tool returns your Maidenhead locator. You can also paste a known locator to convert it back to coordinates.