Using the Ruler to Measure and Set Map Scale

The Ruler tool takes real-world measurements and enables users to interactively set map scale within their drawing.

To Measure Distances:

Use the Ruler [m] tool to measure distances between two points. The ruler displays distance based on the currently defined scale and the drawing’s Display Units. Choose View > Display Units to change units between Points, Drawing Units, or Map Units. Double-click the ruler to open the File > Scale… dialog.

  1. Choose the Ruler [m] tool.
  2. Press and drag to place its beginning point, release to place its end point.
  3. Grab either end of the ruler to adjust its beginning and end points, or the middle of the ruler to reposition.

To Calibrate a Custom Map Scale:


When tracing an existing map or aerial photograph, it is often easiest to calibrate a custom map scale based on the image that is being traced. You will need a known ground-distance from the image in order to calibrate the scale (on a scanned map or photograph, this can be an existing scale bar or a recognizable feature for which you know the length).

  1. Choose the Ruler [m] tool.
  2. Drag the ruler to place it between two known points. Initially the ruler shows an arbitrary distance.
  3. Do one of the following:
  • Double-click the ruler to open the scale calibration window.
  • Choose File > Scale… from the main menu.
  • Choose File > Map Size & Units… from the main menu.

4. Choose the map units from the drop-down list (for example, miles).
4. Enter the ground distance of the length measured (for example 24 miles) and the scale will be adjusted accordingly.

Ruler, scale bar, and drawing are now calibrated to the proper scale.