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Measured AngleAcute
45.00°(Outer: 135.00°)
Ready: Drag angle arm handle or vertex to measure. Output updates continuously.
Augmented Reality (AR)
Camera AR Protractor
Use your device camera to measure angles on physical objects in real-time with augmented reality crosshairs.
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STEP 1
Move center circle to angle corner, then rotate arm to match edge.
Angle45.0°
Angle45.0°
Sim Tilt:0.0°
Point camera flat against the two edges. Tap Freeze Snapshot to lock and read the angle.
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Comprehensive Geometry & Engineering Handbook
Online Free Protractor & Screen Ruler · onlinefreeprotractor.com
✓ 100% Client-Side Private · Local RAM
⠿📏 Screen Ruler
Dist: 0.00 cm📹
Live Camera AR Protractor
Measure real-world angles directly on physical objects, walls, roof pitches, or woodwork using your camera feed.
100% Private: Video is processed locally in real-time.
Point camera flat against the two edges. Tap Freeze Snapshot to lock and read the angle.Drag Blue Center to vertex · Drag Arm Handle to rotate
⠿💳 Card
85.60 × 53.98 mmScale: 100 px = 10.0 cm
Bubble Level
MEASURED ANGLE OUTPUT
45.00°
ACUTE
Outer: 135.00° · 0.7854 rad
Supplementary
135.00°
Complementary
45.00°
Trigonometric Ratios
sin: 0.7071 · cos: 0.7071
Device Calibration
113.0 PPI · 1:1 Scale
RECORDED ANGLE PINS
| # | Angle (Deg) | Radians | Type |
|---|
Primary ScaleInner Scale
45.00°Acute
Outer Scale135.00°
Angle Relationships
Supplementary (180°-θ):135.00°
Complementary (90°-θ):45.00°
Reflex (360°-θ):315.00°
Trigonometric Values
sin(θ):0.7071
cos(θ):0.7071
tan(θ) (Slope):1.0000
Circle Geometry
Arm Radius:200 px
Arc Length:157.08 px
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Recorded Measurements0 Pins
| # | Label | Degrees | Radians | Class | Action |
|---|---|---|---|---|---|
| No pinned angles yet. Click canvas to place ray pins or click "+ Save Reading". | |||||
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AR Workflow
How to Measure Real-World Physical Angles
Follow these steps to align the augmented reality protractor over real objects like stairs, roofs, and tools.
01
Allow Camera Access
Click Start Camera and tap Allow in your browser. On mobile devices, tap Flip to toggle between rear and selfie cameras.
Encrypted Local WebRTC
02
Enable Tilt-Sync Protractor
Turn on Tilt-Sync to automatically orient the protractor's baseline with your device's physical gravity angle as you tilt your phone.
Gyroscopic Angle Tracking
03
Freeze Frame & Measure
Click Freeze Snapshot once the object is framed. Position the vertex and arm handles directly over the frozen snapshot to read degrees.
Zero Upload Latency
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Camera AR Support
Live Camera AR Protractor FAQs
Learn how augmented reality video stream, camera security, and tilt sensors work for measuring real-world angles.
Is my camera video stream transmitted or recorded on any server?↓
No, never. The video stream is processed completely client-side inside your browser via standard HTML5 WebRTC. No video frames, camera snapshots, or audio data are ever transmitted or saved to any external servers.
How does Tilt-Sync work with my phone's gyroscope?↓
When Tilt-Sync is enabled on a mobile device, the app reads your device's built-in accelerometer and gyroscope orientation. As you tilt your phone against a wall, roof slope, or car panel, the protractor's baseline automatically levels itself against physical gravity, giving you hands-free plumb incline angles.
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What is the Freeze Snapshot feature?↓
Holding a device steady while dragging interactive measurement rays can be tricky. Clicking Freeze Snapshot captures the exact live video frame into a still canvas image. You can lower your phone, adjust measurement handles comfortably, read precise degrees, and export the annotated screenshot.
Why does my browser ask for camera permission?↓
Modern web browsers enforce strict security policies that require explicit user consent before activating the camera feed. Once you grant permission, the video is rendered solely on your local screen.