The Aviation Standard: DDM
ICAO, the FAA, and virtually all aviation GPS units (Garmin G1000, G3X, Avidyne, ForeFlight) display coordinates in DDM format: 47°36.374'N 122°19.926'W. The minute-based system is convenient because 1 minute of latitude = 1 nautical mile, making mental math intuitive during flight.
How to Enter Coordinates in ForeFlight
In ForeFlight, tap the search box and type coordinates in the format: N47 36.374 W122 19.926 or 47.6062,-122.3321 (DD format also accepted). The app will parse most common formats automatically.
How to Enter Coordinates in a Garmin G1000
Press FPL to open the flight plan page. Select a waypoint field and press ENT. Use the inner/outer knob to enter the coordinates. The G1000 defaults to DDM — enter degrees, then decimal minutes. For ICAO waypoints, entering the identifier is simpler when possible.
International Aviation: DDMM.MMM Format
ICAO uses the format DDMM.MMM for flight plans filed with ATC. For example, N4736.374 W12219.926. This is DDM without degree or minute symbols, for telex/AFTN compatibility. The converter above handles this format.
Airspace and TFR Coordinates
NOTAMs and TFRs are often issued with coordinates in a mix of formats. The FAA frequently uses DMS (47°36'22\"N 122°19'55\"W) in legal text, while charts use DDM. The converter above handles both.
Coordinate Converter
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