Guide
How it works
- 1
Open the meter
The page loads instantly. No account, no setup.
- 2
Grant motion access
On iOS, tap Enable on the prompt - permission must be requested from a user action, so we only ask when you tap.
- 3
Zero and measure
Rest the device on your reference surface and tap Zero, then move it to your target and read the angle.
- 4
Fall back when needed
No sensor or a denied prompt? The two-needle protractor, camera mode, and manual entry all work without one - the tool never becomes unusable.
Sensor placement
Where to put the phone
The meter reads the phone's tilt, so the phone is the tool. Rest one long edge flat against the surface you're measuring a bench, a plank, a wall and the angle between that surface and level is your reading.
To measure a difference rather than an absolute tilt, lay the phone flat on your reference surface first and tap Zero. Everything after that reads relative to that baseline.
Flat on a table reads about 0°; stood upright reads about 90°. Keep the phone still for the steadiest number.
No sensor
Two-needle protractor: measure any corner on screen
The Protractor is a two-needle bevel dial that runs on any device , no gyroscope required. Its needles extend past the dial rim, carrying a faint guide line out over the content you're measuring. Drag one needle onto each edge of a corner and the readout shows the angle between them instantly.
Snap to 0.1° or 1° grid increments for precision. Switch to reflex angle mode to measure the long way around corners past 180° (up to 360°). Lock either needle as your reference while you swing the other , perfect for matching a bevel or checking a series of cuts. Keyboard operators can steer the active needle with arrow keys and press [ / ] to swap which needle moves.
Measure from photos
Camera mode: overlay a protractor on the real world
Camera mode puts a live protractor scale over your camera view, centred on the corner you're measuring. Point the camera at any corner , a mitre joint, a roof peak, a stair stringer , and a protractor overlay appears automatically.
Tap the screen to freeze the frame, then drag the two lines onto the corner's edges. The angle updates live as you adjust. Open a photo from your gallery instead of the live camera if the lighting is better or the corner is hard to reach. Save the annotated PNG for job records or client reports. All processing happens in your browser; nothing is uploaded.