Measure angles with your phone — no protractor needed. We compare 6 angle finder apps for accuracy, calibration, and real-world usability on Android and iPhone.
You are installing a shelf bracket and need to know the wall angle. You are cutting trim and need the exact miter angle. You are checking if a ramp meets ADA slope requirements. In all these cases, the traditional answer is a physical protractor, angle finder, or digital inclinometer — tools that cost $15–$80 and live in a toolbox you may not have with you.
Your phone has a built-in accelerometer and gyroscope that can measure angles with surprising accuracy — often within ±0.1° when properly calibrated. The only question is which app makes the best use of those sensors.
We tested six angle finder apps on real-world tasks: checking miter angles on baseboard trim, measuring roof pitch from the ground, verifying a wheelchair ramp slope, and leveling a TV mount. Here is what we found.
This app does not just find angles — it turns your phone into a complete measurement instrument with four distinct modes and professional-grade features.
Available on
A long-standing app with three modes: camera clinometer (overlay angle on live camera view), clinometer (absolute angle measurement), and bubble level (relative leveling). The camera mode is unique — you can measure the slope of a distant object by aligning reference lines on the camera view.
Camera-based slope measurement for distant objects
Clean interface with multiple color schemes
Full-screen mode for easier reading
Calibration is basic — no flip calibration or profiles
No tolerance guidance or confidence indicator
No measurement sharing
Ads in the free version
Uses the arctangent of gravity to calculate angles. Offers both absolute and relative angle modes — relative mode lets you zero the angle on any surface and then measure relative to it. Saves readings to a history database.
Relative angle mode (measure angle between two surfaces)
History with chart/list views
Simple, focused interface
Ads throughout the app
Limited calibration options
No tolerance guidance
Interface feels dated
A visual protractor that uses your camera. Place two markers on a camera-paused image to calculate the angle between them. This is a different approach — instead of using the accelerometer, it uses visual alignment on a photo.
Measures angles on photos — useful for objects you cannot place your phone against
Free and ad-free
Simple and lightweight
Accuracy depends on your marker placement (human error)
No accelerometer-based measurement — cannot measure tilt or slope
No calibration (not applicable to this approach)
Not useful for leveling or inclinometer tasks
A basic bubble level that also shows the angle in degrees. Simple bullseye interface. Calibration is available but single-point only (no 180° flip). The main issue is aggressive full-screen ads between measurements.
Simple and fast for basic leveling
Shows angle in degrees
Heavy ads that interrupt workflow
Single measurement mode
Basic calibration
Android only
Since iOS 12, the Measure app includes a level. It shows degrees with a green flash at 0°. You can zero it on any surface for relative measurement. Decent for quick checks.
No download needed
Clean Apple design
Relative zeroing
Single mode only (surface level)
No angle gauge or inclinometer mode
No tolerance guidance
No measurement sharing or history
iPhone only
| App | Angle Measurement | Calibration | Modes | Units | Hold | Tolerance | Ads | Price | Platforms |
|---|---|---|---|---|---|---|---|---|---|
| Yes (inclinometer) | 180° + profiles | 4 | °, %, mm/m, ratio | Yes | OK/NEAR/OUT | None | Free | Android, iOS | |
| Clinometer + Bubble Level | Yes (camera + sensor) | Basic | 3 | ° | No | None | Free/Pro | Free/$1.99 | iOS, Android |
| Angle Meter | Yes (absolute + relative) | Limited | 2 | ° | No | None | Yes | Free | Android, iOS |
| Protractor | Yes (visual/photo) | N/A | 1 | ° | N/A | None | None | Free | Android, iOS |
| Gamma Play Level | Basic (degrees) | Basic | 1 | ° | No | None | Heavy | Free | Android |
| Apple Measure Level | Degrees only | Zero-point | 1 | ° | No | None | None | Free | iOS |
With proper calibration, modern phones typically achieve ±0.1° to ±0.3° accuracy. Without calibration, readings can be off by 1° or more due to sensor offset. Always calibrate before critical measurements.
Yes — the Protractor app uses camera-based visual measurement for this. Clinometer + Bubble Level also has a camera overlay for distant slope measurement. For touchable surfaces, accelerometer-based apps (like Bubble Level & Angle Gauge) are more accurate.
A level tells you if something is horizontal (0°) or vertical (90°). An angle finder measures any angle — 17.3°, 45°, 82.6°. Most dedicated level apps include angle measurement, but basic levels (Google, Apple) do not.
Your phone is a legitimate angle-finding tool — if you pair it with the right app. For the most complete package — 4 modes, real calibration, multiple units, tolerance guidance, and zero ads —