How to Measure Area With a Handheld GPS
- 1). Turn on the GPS and set it to "Walking" mode. Set the display to show the distance traveled on this trip. Assume you are attaining the area of a rectangular stretch of land.
- 2). Walk the length of the land area then note the distance traveled on the GPS in miles. Walk in a straight line by keeping the same cardinal direction on the GPS throughout the walk. For example, the distance might be 1.4 miles north.
- 3). Walk the width of the land area, keeping a straight bearing, and note the total distance traveled for the trip. For example, the trip distance may be 3.2 miles.
- 4). Subtract the length from the total trip distance to obtain the width in miles. Now you have 3.2 miles minus 1.4 miles, which equals a width of 1.8 miles.
- 5). Multiply the length times the width to get the area of the land in cubic miles. Completing the exercise leads to 1.4 miles times 1.8 miles, or 2.52 square miles.
Source...