How to Use Handheld GPS Units to Measure Acreage

By Fred Decker

GPS navigation devices can do a lot more than steer you between Point A and Point B. Depending on your model and its features, they can also help you avoid traffic jams, lead you to the most stunning view in a state park, or measure the acreage of a piece of land. Your GPS not as accurate as a professional surveyor for calculating acreage, but it's still useful as a quick reference. Some models will perform the calculation for you, otherwise you can do the math yourself.

Garmin GPSMAP 62

Step 1

Ensure that the Garmin has fresh batteries, and take it outdoors. Turn on the unit, and wait while it acquires a satellite signal. A question mark will flash on the screen until the satellites are located.

Step 2

Travel to the area you want to measure. From the main menu, select "Area Calculation" and then "Start."

Step 3

Walk around the edges of the area you want to measure. The GPS will record your position periodically, tracking the distance you've walked in each direction.

Tap "Calculate" on the handheld's menu. If the area measurement is expressed in a unit other than acres, press "Change Units" and then "Enter." Select "Acres" as your unit and then press "Enter" again to view the result.

Manual Calculation

Step 1

Set your handheld to start a new track. For example on a Magellan Explorist 310, you'd press "Back" from your map screen, and select "Start." Confirm that you want to clear the current track and start a new one.

Step 2

Walk the perimeter of the area you want to measure. When you're finished, view the track on your map and write down its measurements.

Step 3

Calculate the area of a square or rectangular property by multiplying its length by its width. For example, if the area is 600 feet deep and 80 feet wide, the area is 48,000 square feet. For a triangular property, divide that area by half. To measure oblongs, polygons or other complicated shapes, divide them into rectangles, triangles or half-circles and calculate the square footage of each portion separately.

Divide square footage by 43,560, the number of square feet in an acre. In the example given previously, 48,000 square feet equals approximately 1.1 acres.