Changing Lat-Lon to Garmin Decimal.

Try http://www.gpsvisualizer.com/calculators . It will give you both the terminology and the conversion.

Coordinates can be expressed in several different formats.

They are most commonly Degrees Minutes Seconds (DDD MM SS), Decimal Degrees (DDD.DDDD), or Degrees Decimal Minutes (DDD MM.MMM).

The last format is the most common in current GPS models. The second one is the one we use in Custom POI files.

Here are some examples of the same coordinates expressed in different formats.

Degrees, Minutes and Seconds
DDD° MM' SS.S"
N 32° 18' 23.1" W 122° 36' 52.5"

Decimal Degrees
DDD.DDDDD°
N 32.30642° W 122.61458°

Degrees and Decimal Minutes
DDD° MM.MMM'
N 32° 18.385' W 122° 36.875'

You don't say why you want to do this - no doubt you have your reasons

...but quite often you can choose the display format (for example in Google Earth, Mapsource etc). You can also change your Nüvi to match.

Life's easiest, if you set everything to ddd.ddddd°

Using MM's example
N 32° 18' 23.1"
there are 60 seconds per minute
60 minutes per degree
the example is 32 degs, 18 mins, 23.1 sec
so 23.1 ÷ 60 = 0.385 mins so the examples becomes 32 deg, 18.385 minutes
18.385 ÷ 60 = 0.30642 deg
32.30642 degrees

I don't have anything against using an aid but often it helps to understand how it's done

I am using Google Earth to create a POI file of all the Weigh Stations in California.

Google earth shows the Lat/Long Coordinates, and I THOUGHT that I had to find a way to convert them to Garmin format.

I'm going to take a look through google earth for the display formats parameter...

Thanks!

See:
http://www.poi-factory.com/node/9323

Thanks Y'all

--I've been wondering about this myself. This gives me some reference to begin to understand it all from!

Again.. THANKS TO ALL!!

http://www.gpsvisualizer.com/calculators was suggested as a converter to do this, but it appears that it only has a function to change Garmin Decimal to LAT-LONG not the other way round. Am I missing something? or is that function buried somewhere that I haven't found?

If you're looking for a way to convert 'degree' coordinates to decimal' coordinates, 'POI Verifier II v2.0.0.3' will mass-convert a POI file that contains 'degree/minutes'seconds' to a POI file containing decimal coordinates.

RT

Good info!

Yes, great info.

Whenever I have a curiosity about something GPSr related, a quick search finds a thread with discussion!

Thanks!

In Google Earth, on the tool bar click on tools go down to options and click on that, make sure your under the 3D view tab then on the left side is Lat/Long settings, highlight: Decimal, Degrees and hit apply, the GPS format will show up on the main map bottom left! This is what I use.
I hope this helps!