Camera Angle Finder
Last updated: September 29, 2026
A camera angle finder puts a transparent protractor over your phone’s live camera feed, so any corner, roofline or joint can be read in degrees without printing a template or drawing a single arc by hand. Open the page, allow camera access, and the overlay is already there: line it up with the edge of the object and read the number.
The video never leaves your device. Frames are drawn straight onto a canvas in the browser and dropped again a moment later, so there is nothing to upload, no account to create and no app to install. The same page works on a phone, a tablet or a laptop with a webcam.
Angle Properties & Complementary
Keyboard Shortcuts:
Measurement History
Saved in this browser only - never uploaded.
| Time | Mode | Degrees | Radians | Slope |
|---|---|---|---|---|
| Every angle you lock is logged here. | ||||
How to measure an angle with your phone camera
This page opens with the camera mode already selected, so the only permission involved is camera access itself – iOS asks once per visit, while most Android phones and desktop browsers start straight away. Frame the corner so that both edges run into the shot and the point where they meet is visible, then drag the centre handle of the overlay onto that vertex.
Pull the baseline handle onto one of the two edges until the line lies along it, then move the second handle onto the other edge. The readout follows every movement. When the number matters, press freeze to stop on the current frame, nudge the arm with the fine-tune buttons in tenth-of-a-degree steps, and press lock so the measurement stays put while you write it down.
Getting a reading you can trust
Angles only come out true when you look square-on at the surface they belong to. If you stand to one side, perspective stretches the picture and a corner that is genuinely square can read as five or ten degrees out. Move your feet instead of twisting the phone: stand directly in front of the object, keep the phone level, and try to make the camera axis perpendicular to the plane of the angle.
Distance helps as much as position. Stand back and zoom rather than holding the phone close with the wide-angle lens, because straight lines bow slightly near the edge of a wide lens. The complementary and supplementary values in the side panel act as a sanity check as well – for a corner that should be square, both of them land on 90°, and if they do not, the baseline is sitting slightly off the edge.
What people measure with it
The everyday jobs are framing and trim work: reading an odd corner before setting a saw, checking whether a stairwell opening is really square, or estimating the pitch of a roofline from the garden. It also works for quick grade checks on a driveway or a ramp, for copying the rake of an existing piece of trim, and for checking that a picture rail is not a degree out after three metres.
Every locked reading can go into the measurement history below the canvas. That history lives in this browser only, and exports as a CSV file whenever you want the numbers in a spreadsheet. When the angle is locked inside a picture you already have, switch to photo mode; when the phone itself is resting flat on a surface, the device tilt mode reads the slope from the gyroscope instead.