A protractor that works the way you'd draw one by hand.
No accounts, no image uploads to a server, no tutorial required. Everything below happens directly in your browser.
1. Add a protractor
Tap or click anywhere on the canvas — a protractor drops in with two rays already in place, so there's nothing to configure before you start dragging.
2. Drag the rays into position
Grab either ray's endpoint and drag it to line up with what you're measuring. The angle between the two rays updates live, shown in the center of the arc.
3. Bring in an image (optional)
Drop a photo onto the canvas, paste one from your clipboard, or use the upload button. Rotate, flip, or zoom it into position before you measure — your protractors stay attached to whatever they're pointing at, even after you rotate.
4. Snap for round numbers
Turn on snapping and pick an increment — 1°, 5°, 10°, 15°, 30°, 45°, or 90° — and dragged rays lock to the nearest one automatically.
5. Export your result
Download a PNG of exactly what's on the canvas, or a CSV with every protractor's center, ray endpoints, and angle — ready for a report or spreadsheet.
A note on precision
This tool measures the angle between two rays you draw — it's as precise as your placement. For photos, zoom in before dragging a ray endpoint for a more exact result. For anything safety-critical or load-bearing, confirm with a physical protractor or a professional instrument.