Tools

latlongdd2.xls (download)

Conversion of latitude/longitude (DMS) to decimal degrees (DD)

 William R. Elliott, Missouri Department of Conservation

29 Jan. 2007 

This Excel spreadsheet is provided to the public domain for those needing a tool to convert latitude/longitude in the DMS system (degrees, minutes, seconds)  to decimal degrees (DD), which can be used in a Geographic Information System (GIS). This spreadsheet can convert batches of coordinates that are typed or pasted from a table in Access, Excel or DBF formats. One can then paste the converted data back to a table that has the appropriate fields. ESRI products, like ArcView and ArcMap, can utilize the DD coordinates (latitude is Y, longitude is X), as well as UTM coordinates and other systems.

See the worksheet <100°W for longitudes less than 100°W. See >100°W if 100°W or larger.

The dither worksheet shows how rounding or randomization of decimal degree coordinates provides a good way to dither locations; that is, to randomly move a point from its true location in a Geographic Information System. One can retain the true location in a table, but also have dithered coordinates in the same table to use in a GIS. This is useful for presenting caves on large-area maps without revealing precise locations.