Google Earth’s free version supports measuring distance along either a line or a path. A line incorporates just two points; a path can have multiple points, enabling you to measure the distance on a road with curves or turns by entering several points. The measurement tools are on the Ruler window, accessed via the Ruler icon on the toolbar.
Select the Ruler icon on the toolbar to launch the Ruler dialogue box. Check “Mouse Navigation” if it is not selected already. Mouse navigation enables Earth to recognize movements and selections of the mouse.
Select the distance units from the Map Length drop-down; for example, Nautical Miles.
Drag your mouse from one point to another. The Ruler automatically updates the distance based on the unit you chose. The Ground Length also updates -- while the figure may be the same as the Map Length, Ground Length takes into account elevation or topographical features.
Change the units under Map Length to see the distance in another unit, such as kilometers. Click “Clear” to delete the existing line.
Click the “Path” tab, which enables you to select multiple points and measure the distance between them all.
Zoom into the area you want to measure by dragging the zoom icon slider up. Zooming in makes it easier to be precise when creating points that should follow a road or particular route.
Double-click your beginning point (in this example, the town of Knappa) and release. Click your next point and release. As you apply points, Google Earth creates a line between each point. Continue to add points where your route curves or bends. The more points you add, the more precise you can be in your route.
Adjust your path as needed by selecting a point and dragging it to another, more precise, location. You can drag any point to any location on the map. When you select a point, the cursor becomes a hand and the point turns green to indicate that it is active. When you release the point, the point turns blue.
Tips & Warnings
- The points on a line or path are either green, blue or red depending on how you are interacting with them. The point is blue when it is the most recent point you entered or selected -- any point added after this extends from this blue point. A point is red when it is inactive. A point turns green when you select it to drag it to another location.
- You can save your selected route by clicking "Save." Google Earth saves it in Keyhole Markup Language format, an XML based format used for displaying geographical information.