⚙️ Settings: exact value, photo, grid & more
Drawing didn't show? Tap to redraw.
💡 No need to select anything first — just drag. Real-world use: open 🎥 Camera and aim at the object or use ⛶ Fullscreen and hold the phone edge against it.
Online Protractor — Free & Precise
Measure any angle on screen, on a photo or via camera. Drag, rotate and see the live reading. No signup, no upload.
Measure in 4 steps
Place — drag the black point to the corner.
Align — rotate blue over one side.
Measure — drag red and read the value.
Save — export PNG or copy the value.
Angle types
FAQ
Why is my angle wrong?
90% of the time the black point is not exactly on the vertex. Drag it right into the corner, then align blue.
How to measure a photo?
Click 📷 Photo, pick the image, drag black to the corner and align the arms. Adjust transparency if needed.
What are complementary and supplementary?
Complementary adds to 90° (38° + 52°). Supplementary adds to 180° (38° + 142°). We show both live.
How to type an exact value?
Type in “Exact” and click Go — great to check 30°, 45°, 60°, 90° homework.
180° or 360°?
Use 180° for school and normal angles. Use 360° for reflex angles over 180°.
Is my photo uploaded?
No. Everything runs locally via Canvas. Close the tab and it is gone.