Tool
Angle finder: measure any angle in your browser
0.0°
Choose a mode.
Tilt your device and the reading tracks it live. On iOS you must grant motion access first - tap the button below.
Higher is steadier but slower to settle. Lower tracks fast movement.
Rest the device still for the steadiest reading.
Drag either needle around the dial, or focus it and use the arrow keys. Both needles make an angle - arm A is the reference, arm B the target. Hold Shift for 10° steps, or press[ / ] to switch needles.
Point the camera at the corner, then tap the screen to freeze the frame. A protractor scale sits over the view, centred on the corner - drag the two lines onto its edges and the angle reads live as you move them. Save the annotated photo; the image is read in the browser and never uploaded.
Start the camera, or open a photo from your gallery.
Tap anywhere to capture
How to measure a corner
- 1
Start the camera or open a photo from your gallery. Nothing is uploaded.
- 2
Frame the corner so both edges of the angle are in view, and use the protractor scale to line it up.
- 3
Tap the screen anywhere to freeze the frame - the angle stops moving.
- 4
Drag the lines put the centre dot on the corner and lay one line along each edge - the scale re-centres on it.
- 5
Download to save the photo with the angle drawn on it.
How to measure with your phone
- 1
Lay the phone flat on any surface and tap Zero if you want to measure a difference from here.
- 2
Rest the long edge of the phone against the surface you're measuring.
- 3
Tilt to match , the diagram tracks your live angle as you move.
- 4
Tap Hold to freeze the number before you write it down.
Keep the phone still for the steadiest number; if the reading jitters, raise Smoothing below.
History
Saved readings appear here. They stay on this device - nothing is uploaded.
Four ways to measure
Sensor reads your device's orientation for live tilt. Protractoris a two-needle bevel dial that works on any device, sensor or not - the needles run long, past the rim, so you can lay one on each edge of a corner and read the angle between them, with snap, reflex, and per-needle locks.Camera overlays a protractor scale on a live view or a photo, centred on the corner; drag the two lines onto its edges - tap the screen to freeze the frame, then download the annotated photo.Manual takes a typed angle.Zero sets the current angle as the new baseline so you read a difference; Holdfreezes the number so you can write it down.
Free Online Angle Finder: Measure Any Angle in Your Browser
Angle Finder is a free online angle finder that turns any smartphone, tablet, or computer into a precision angle measure tool. Whether you need a digital angle finder for woodworking, a protractor angle finder for construction, or an angle finder calculator for quick unit conversions, this tool delivers professional-grade measurements without installing any angle finder app.
Unlike a physical protractor that only shows degrees, the digital angle finder tool displays readings in multiple units at once: degrees, radians, gradians, percent slope, roof pitch (rise-over-run), and degrees-minutes-seconds (DMS). That suits tradespeople who switch between measurement systems, carpenters setting saw bevels, roofers checking roof pitch, machinists working in radians, and engineers calculating percent slope.
The angle finder online works three ways. First, the tilt sensor mode uses your device's gyroscope: rest the phone's long edge on any surface and watch the live readout update to a tenth of a degree. Tap Zero on a reference surface to measure relative angles, perfect for checking if a shelf is level or matching two bevel cuts. Second, the two-needle protractor mode works on any device, sensor or not. Drag one needle onto each edge of a corner; the needles extend past the dial rim so you can align them precisely. Snap to 0.1° increments, lock a needle as your reference, or switch to reflex angle mode for corners greater than 180°. Third, camera mode overlays a protractor tool on the live camera view or a photo from your gallery. Point at a corner, tap to freeze, drag the lines onto the edges, and save an annotated PNG, with nothing uploaded.
Searching for an angle viewer online or a free angle finder online often leads to cluttered sites with ads and tracking. Angle Finder is different: no accounts, no analytics, no cookies, no cookie banner. The angle measure app respects your privacy, every calculation stays in your browser. For students and educators, it's an online protractor that demonstrates acute angle measure, obtuse angles, and reflex angles instantly without handing out plastic tools.
Need to convert a value you already have? The built-in angle finder calculator and unit reference page let you switch between degrees, radians, gradians, percent slope, and roof pitch instantly. Export readings as CSV for job sheets, or save annotated camera photos for documentation. Whether you're checking a right angle measure for square corners, setting a mitre saw, or verifying a ramp's slope for accessibility compliance, this angle measure tool handles it all.
Ready to measure? The meter is live above, just rest your phone on a surface, drag the protractor needles onto a corner, or point the camera at an angle. No signup, no install, no waiting. For a deeper walkthrough of sensors, the two-needle dial, and camera measurement, visit the how it works guide or the comprehensive angle finder guide.
Features
What it does, plus the small things most tools skip.
Sensor
Measure tilt and angles live
Lean your phone against a surface and read the angle in degrees, radians, slope, or pitch. Zero it any time to measure a difference, not just an absolute tilt.
Protractor
Two needles, one bevel gauge
A draggable two-needle dial that works on any device, sensor or not. The needles run long, past the rim, so you can lay one on each edge of a corner, snap to the grid, take the reflex angle, and lock either needle as your reference.
Camera
Measure on a live view or a photo
A protractor scale sits over the live view, centred on the corner. Tap the screen to freeze the frame, drag the two lines onto its edges, and save the annotated photo - or open one from your gallery instead. Nothing is uploaded.
Units
Degrees, radians, slope, pitch
Convert between degrees, radians, gradians, percent slope, and rise-over-run roof pitch without leaving the page.
Access
Keyboard and screen reader support
The dial and camera overlay are keyboard-operable, the readout is announced to screen readers, and the interface respects high contrast and reduced motion.
FAQ
Frequently asked questions
How to use an angle finder?
Using an angle finder is simple: open the tool in your browser, choose your preferred mode (sensor, protractor, camera, or manual), and measure. For the sensor mode, rest your phone's long edge against the surface and read the live angle. For the protractor mode, drag the two needles onto the edges of any corner. For camera mode, point at a corner, tap to freeze, then align the lines to the edges. The readout updates instantly in degrees, radians, slope, pitch, or DMS.
How can I use my phone as an angle finder?
Your phone already has the sensors needed. Open Angle Finder in your browser, no app install required. Grant motion permission when prompted, then rest the phone's long edge on any surface to measure tilt. If your device lacks a gyroscope or you decline permission, the two-needle protractor and camera modes still work perfectly for measuring any angle.
Is this a free angle finder?
Yes. There is no account, installation, paywall, or usage limit; every measurement runs in your browser. It has no ads or trackers.
How can an iPhone find an angle?
iPhones have a built-in gyroscope and accelerometer. When you open Angle Finder in Safari and grant motion access, the sensor reports the device's orientation in real time. Rest the phone's long edge on a surface and the live readout shows the angle. You can also use the two-needle protractor or camera mode on iPhone, both work without any sensor at all.
Is this a 360 angle finder?
Yes. The protractor mode supports full 360° measurement. Enable the reflex angle option to measure the long way around a corner (180°-360°), or disable it for the convex angle (0°-180°). The sensor mode reads 0°-360° as you rotate the device. Camera and manual modes also cover the full circle.
How to check angle by phone?
Open Angle Finder in your phone's browser. Choose sensor mode to measure tilt by resting the phone on a surface, protractor mode to drag two needles onto a corner, camera mode to overlay a protractor on the live view or a photo, or manual mode to type in a value. The angle appears instantly in your preferred unit.
What is the easiest way to find an angle?
The easiest way is the sensor mode: open the page, grant motion permission, and rest your phone on the surface. The angle appears immediately, no dragging, no alignment, no setup. If you're measuring a corner rather than a flat surface, the two-needle protractor is just as fast: drag one needle to each edge and read the result.
How can I measure an angle from a photo or camera?
Select camera mode. Point the camera at a corner and a protractor scale appears over the live view. Tap the screen to freeze the frame, then drag the two lines onto the edges of the corner, the angle updates live. You can also open a photo from your gallery instead of using the live camera. Save the annotated image for records. Nothing is uploaded; all processing happens in your browser.
How can I measure an angle without a protractor?
You don't need a physical protractor. Use the sensor mode (rest your phone on the surface), the two-needle digital protractor (drag needles on screen), the camera overlay (point and align), or manual entry (type a known value). All four methods run in your browser and display the angle in degrees, radians, slope, pitch, gradians, or DMS.
Are digital angle finders worth it?
Yes. Readings resolve to 0.1°, units convert automatically, reference angles lock, reflex angles run to 360°, and annotated photos and CSV exports are available. It costs nothing and runs on the phone you already carry.
Can I measure an angle without a motion sensor?
Yes. If your device has no gyroscope, or you decline motion access, the two-needle protractor, the camera overlay, and manual entry all still measure angles accurately. The tilt sensor is a convenience for flat surfaces; the protractor and camera modes work on any device with a screen and require no sensors at all.
New to measuring angles? The angle finder guide covers sensors, the two-needle protractor, and camera measurement in detail.