On-Screen Protractor

On-Screen Protractor is a simple Java application that allows to measure an angle on the screen.

Originally the program was conceived to assess the angle between north and a given point on any map open on the screen, therefore the background of the application window is transparent and the angle is measured from the positive y-axis and clockwise. The application allows to move the origin of reference axes and to rotate the axes as needed.

Minimum Java Development Kit (JDK) version required: 25.0.1
OnScreenProtractor works correctly only in Windows context.
(In linux 'OnScreenProtractor_v0.7.exe' can be started with 'Wine')

This software is released under GNU GPL v3

v0.7 (2026/02/08) - Release Note

• Add menu items:
  • to show a protractor image and scale that image,
  • to show the line passing through points A and O,
  • to show the line passing through points B and O,
  • to set rotation from north,
  • to set the size of angle AOB.
• Two distributions:
  1. with Windows executable.
     
     OnScreenProtractor_v0.7_with_exe.zip (52,8 MB)
  2. minimal. Only jar, resources and source code.
     
     OnScreenProtractor_v0.7_JDK_required.zip (284,4 KB )

On-Screen Protractor project page

How to use on-screen protractor:

Click the left mouse button to drag and drop O, A, B points (hand cursor).

Click the right mouse button to set the origin of axes at the center of the window.

Use the middle mouse wheel or the left and right arrow keys to rotate axes clockwise or counterclockwise. Click the mouse wheel or use the up arrow key to cancel axes rotation.

Click the icon 'Capture' to save the window's content

Use keyboard or menu to have access to further options