How to measure an angle on iPhone
On iPhone, the fastest method is: take a screenshot → upload it into the tool → align → measure → export.
1
Capture a clean screenshot
2
Open the tool and upload
3
Align one side as the baseline
When this helps
Use this when the angle is already on your iPhone screen (a video frame, a PDF, a web page, a diagram, or a photo). Clear edges and a large capture make the reading more stable.
Step-by-step
- 1Capture a clean screenshotTake a screenshot and crop to the angle area. Keep a bit of straight line on both sides so alignment is easier.
- 2Open the tool and uploadOpen the online protractor on your iPhone, tap upload, and select the screenshot from Photos or Files.
- 3Align one side as the baselineRotate/flip and use the grid so one side direction is straight and becomes your reference.
- 4Place the vertex and choose modeMove the center to the vertex. Use 180° for interior angles; switch to 360° when you need a reflex angle (>180°).
- 5Read and exportIf the value looks wrong, re-check alignment and vertex placement. Export PNG/PDF when the reading is stable.
Tips
- Zoom in before you screenshot for better accuracy. Small screenshots make edges jagged.
- If the object is tilted relative to the camera, perspective distortion can bias readings. Prefer a straight-on view when possible.
- If snap makes the value jump, toggle snap mode or turn it off for the last 1–2 degrees.
Related
How to use an online protractor
The general workflow that applies to almost every scenario.
Measure an angle on a screenshot
Copy/paste workflow (best on desktop) once you have an image.
PNG and PDF exports
Save a shareable image or a measurement report.
Angle looks inaccurate
Common causes and quick fixes for wrong-looking readings.