On-Screen Protractor

        2016/02/28 - version 0.5 released

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 JRE version required: 1.7

This software is released under GNU GPL v3


Download OnScreenProtractor

sourceforge.net project page

Download OnScreenProtractor


How to use on-screen protractor:

left mouse button

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

tasto destro del mouse

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

middle mouse wheel

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.

capture image

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


Use keyboard or menu to have access to further options

Key Description

Move the point O (axes origin) to the current position of mouse pointer.

Move the point A to the current position of mouse pointer.

Move the point B to the current position of mouse pointer.
+ Increase the thickness of axes and the font size
- Decrease the thickness of axes and the font size
 Ctrl + S  Save
 Ctrl + Q  Quit application
 Ctrl + M  Hide/show mouse coordinates
 Ctrl + A  Hide/show axes
 Ctrl + Shift + A  Hide/show AO segment
 Ctrl + Shift + B  Hide/show BO segment
 Ctrl + O  Hide/show AOB angle
 Ctrl + E  Hide/show the explementary angle of AOB
 Ctrl + Alt + A  Hide/show NOA angle
 Ctrl + Alt + B  Hide/show NOB angle
 Ctrl + P  Hide/show points' handles
 Ctrl + L  Hide/show letters
 Ctrl + B  Hide/show text background
 Ctrl + R  Degrees/radians
 Ctrl + H  Hide all or show default elements
 F1  Help