Protractor
Measure angles on screen
How to use Protractor
- Drag the center point onto the corner of the angle you want to measure.
- Drag each arm along one side of the angle.
- Read the angle in the box at the top.
About this tool
Measure angles on your screen with a half or full protractor. Drag the two arms to any direction and read the angle between them, plus the reflex angle, in degrees or radians.
Move the protractor by dragging its center, snap the arms to whole degrees or 5° and 15° steps, and add a picture behind it to measure an angle in a photo or drawing. It works with a mouse, a pen or your finger.
- Works on your device. Nothing is uploaded.
- Free, with no sign-up and no watermark.
- No limits on file count or size beyond what your device can handle.
Questions and answers
How do I measure an angle in a photo?
Choose a picture under “Picture behind the protractor”, or drop it on the protractor. Then place the center on the corner and align the arms with the two lines.
What is a reflex angle?
The angle measured the long way around, between 180° and 360°. It is always 360° minus the smaller angle.
Can I set an exact angle?
Yes. Turn on snapping, or click the protractor and use the arrow keys to turn the second arm one degree at a time (ten with Shift).
Is Protractor free?
Yes. Every tool on ImgImage is free to use, with no sign-up, no watermark and no limit on how many files you process.
Does it work on my phone?
Yes. It works in any modern browser on phones, tablets and computers. Large files are processed faster on a computer.