GPScalc is a calculator to convert between geodetic longitude and latitude to UTM eastings and northings and to calculate distance and headings between waypoints with great accuracy.

GPScalc allows you to calculate distances to within 1 cm accuracy between your GPS position fixes. This is based on the condition that start and end points fall within the same UTM zone and the distance between points is less than 1000m. Otherwise, for greater distances it can still calculate within 0.5% accuracy.

Features of GPScalc :

Input style can be ddd.dddddddddd, ddmm.mmmmmmmm or ddmmss.ssssss
Output results can be Metric (meters), statute (miles), or nautical (sea miles)
Built in database to save and recall waypoints
Supports about 38 user selectable ellipsoids to use in conversions
Converts Lat/Long to UTM or UTM to Lat/Long
Converts Lat/Long to Swiss Grid or Swiss Grid to Lat/Long
Resolution is 1 mm and accuracy is better than 1 cm.
Supports Copy-and-Paste between fields.
Conversion results can be exported to the PalmOS notepad utility.
User can choose between four different Heading/Distance measurement methods. These are:
Geodetic Method - Results are equivalent to those calculated by the U.S. National Geodetic Survey reference programs.
Haversine Method - Results are equivalent to those given by GPS devices with built in Heading/Distance functions.
Rhumb line Method - Results are equalvalent to those often used in aeronautical and maritime navigation.
Pythagorean Method - Gives results equivalent to those obtained with line-of-sight surveying equipment like laser range finders.