EasyAcreage is program for WinXP or Vista program that allows you to calculate area from KML files exported out of Google Earth. This means you do not even have to leave your house to measure a field anymore. Simply use the free version of Google Earth, mark the area you wish to measure, save it as a KML file and drag and drop it onto EasyAcreage. Voila!
Using EasyAcreage you can use the KML export methods that exists in the standard free version of Google Earth and get the same results at a fraction of the cost.
Easy steps to calculate area
Find the statelite view of the field/area that you want to measure in Google Earth
Click on Menu -> Add -> Path and mark the path as shown on the screenshot below
Next step is to go Menu -> File -> Save -> Save Place As (Ctl+S) and save the file. (Remember to use KML and not KMZ format)
Drag the file into the larger rectangular List View block of EasyAcreage and almost immediately it will display the calculated area.
You can change the Area measurement unit as Hectares, Acres, square meter, square kilometer, square feet or square miles
You can change the Distance measurement unit as meters, kilometers, feet or miles
If you change any of the settings, the program will automatically remember it the next time you run it.
You can drag and drop more than one file simultaneously. Just click on each file name to instantly calculate its area.
The measurement results shows the Area and the distance of the outer perimeter of the field
The measurement results is amazingly accurate (typically about 1% for a small area the size of a tennis court).
Before you buy, make sure you download the demo version an try it out. It has a restriction that will only cause it to display areas that are less than one acre. But this should at least give you an opportunity to make sure you are happy that the program is running as expected on your PC.