> For the complete documentation index, see [llms.txt](https://help.onform.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.onform.com/coaching/analyze/using-the-angle-tool.md).

# Measure an angle

Measure a joint angle, such as a knee or elbow bend, or the tilt of a line from level, with Onform's angle and line-with-angle tools on iPhone and iPad.

Works on: iPhone and iPad. The web app doesn't have the angle tools. The Android app has a smaller set of drawing tools, and we're still confirming whether it includes them.

Onform has two tools for angles:

* **Angle** measures the angle between two connected lines, such as the bend at a knee, elbow or hip.
* **Line with angle** measures how far one line is tilted from level, such as the shoulders at address, a forward lean at the start of a sprint, or a bowler's front leg.

## Before you start

* Pause the video on the exact frame you want to measure. Step frame by frame with the arrows either side of play, or drag across the video.
* Film side-on to the movement where you can. Angles measured on a video taken at a slant won't match the real joint angle.
* If neither tool is in your drawing toolbar, add one: tap a slot in the toolbar, tap it again, then pick the tool. See [Draw on a video](/coaching/analyze/finding-and-using-the-drawing-toolbox.md).

## Measure a joint angle

The example below measures a knee bend: the angle between the thigh and the shin.

1. Tap the pencil to open the drawing tools, then tap the angle tool.
2. Put your finger on the hip and drag to the knee, then lift your finger. The point where you lift your finger is the corner of the angle.
3. Onform adds the second line from the knee, with a dot at each end. Drag the free end down to the ankle.
4. Read the angle shown at the knee. It updates as you move the lines.

To fine-tune it, drag any of the three dots. To move the whole angle, drag one of its lines. The same steps work for an elbow at release, a hip hinge or a wrist angle at the top of a swing.

## Measure the tilt of a line

1. Tap the pencil, then tap the line with angle tool.
2. Draw a line along the body part or object you want to measure, such as from one shoulder to the other, or along the spine.
3. Read the angle on the line. It's measured from level, so a flat line shows 0 and an upright line shows 90.

Tip: the plain line tool also shows its angle when you draw it almost level or almost upright. It's a quick way to check whether a club shaft is vertical or a pair of hips is level.

## Compare angles between reps

Measure the same angle at the same moment on two reps, for example the front knee at foot strike on this week's sprint and last month's. To see them side by side, put both videos in [Compare](/coaching/analyze/how-to-compare-videos.md) and draw on each one.

## If something goes wrong

| What you see                             | What to do                                                                                                                 |
| ---------------------------------------- | -------------------------------------------------------------------------------------------------------------------------- |
| "Angle Tool is not available in 3D"      | The angle tool works on the video, not the 3D view. Switch back to the video to measure.                                   |
| The angle is hard to place accurately    | Zoom in on the video with two fingers first, or use an iPad for a bigger view. Then drag the dots exactly onto each joint. |
| You can't find the angle tool on the web | The web app doesn't have angle tools. Use an iPhone or iPad.                                                               |
| The reading looks wrong                  | Check the camera was side-on to the movement. A video taken at an angle changes what the tool measures.                    |

Still stuck? Email <support@onform.com> with your device, the Onform version and a screenshot.

## Related

* [Draw on a video](/coaching/analyze/finding-and-using-the-drawing-toolbox.md)
* [Compare two videos](/coaching/analyze/how-to-compare-videos.md)
* [Record a Voice-over](/coaching/analyze/how-to-record-a-voiceover.md)
* [Analysis tools at a glance](https://github.com/Onform-Inc/onform-docs/tree/main/get-started/how-onform-works/analysis-tools.md)


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