Angle finder
Angle Finder Online – Measure Angles Instantly
Angle finder online — drag the digital protractor to find any angle instantly. Place the center on the vertex where two rays meet, align the baseline, and the tool classifies acute, right, obtuse, straight or reflex live with interior and reflex readings in degrees or radians.
Updated Online Protractor
Keyboard: Tab handles, arrows nudge 1px center / 1° ray (Shift 10px / 5°), R reset, G grid, L lock baseline, Z undo, Shift+Z redo, +/- zoom. Endpoint magnifier shows while dragging. Drag center, baseline ray, second ray. Snap preview before commit. Image stays local — never uploaded. Press Esc to exit fullscreen.
Camera stays local — capture is processed in your browser
Watch the pill next to the reading: it switches from Acute → Right → Obtuse → Straight → Reflex. About accuracy
0° < angle < 90° — sharp, like 30°, 45°, 60°.
Exactly 90° — the corner of a square.
90° < angle < 180° — wider than square.
A straight line. In 180° mode it’s the flat edge.
The larger side. Try 270°, or toggle “Measure reflex”.
How the finder works
- Acute if inner angle < 90°.
- Right if exactly 90° (green highlight in the tool).
- Obtuse if 90° < inner < 180°.
- Straight if 180°.
- Reflex if 180° < inner < 360° — use 360° mode or the reflex toggle.