How to Use the Measure App on iPhone or iPad

The Measure app, first seen in iOS 12, can do the job of a tape measure. This article explains how to use the ruler aka Measure app on your iPhone.

How to Take a Single Measurement With the Measure App

You can use the iPhone Measure app like you would use a tape measure to take a single measurement. Here's how:

1. Launch the Measure app. It comes pre-loaded on your iOS device and looks like a ruler. When the app starts, it will ask you to move the device around, which lets it calibrate distances on the surface you want to measure. Keep it pointed at the surface you want to measure as you move it around.

2. Point the dot in the middle of the screen at the starting point you want to measure, then tap the Plus.

3. Move the point to the end of the measurement and tap the Plus a second time.

4. If you need to redo a measurement, tap the Back arrow at the top left of the screen to repeat the last dot, or tap Clear to start over again.

5. To copy the measurement information to the clipboard, tap the measurement to open a dialog box, then tap Copy.

6. If you're satisfied with your result, tap the Shutter release to take a photo of the scene that includes the measurement.

How to Take Multiple Measurements With the Measure App

You can use the Measure app to measure different aspects of the same object, such as length and width. You can even measure length, width, and diagonal, as long as each measurement intersects, with a point in common. You can’t measure two lines that don’t intersect, like parallel lines.

1. Open the Measure app. Keep it pointed at the surface you want to measure as you move it around to calibrate.

2. Point the dot in the middle of the screen at the starting point you want to measure, then tap the Plus.

3. Position the point where you want to begin the second measurement and tap the Plus. Then, move it to touch some point on the original measurement line and tap the Plus again.

4. You can take as many measurements as you want, as long as each one intersects with a different line.

5. Tap any measurement to open a dialog box, then tap Copy so you can save the information to the clipboard.

6. When you’re done, tap the Shutter release to take a photo of the scene.

How to Measure the Area of a Rectangle With the iOS Measure App

If the Measure app recognizes there’s a rectangular object on the surface under the phone, it will automatically create a box around the object.

1. To automatically detect a rectangle, you need to be working in a well lit area and the object needs to closely conform to a rectangular shape. In some cases, the iPhone won't detect it and you'll need to measure the dimensions manually.

2. If you want this measurement, tap the Plus and the measurements will appear automatically, along with the area of the object.

3. You can tap the area to open a dialog box that displays more details about the measurements, including the diagonal dimensions of the rectangle.

How to Use the iPhone's Level

The Measure tool also includes a level. You used to be able to find this feature in the Compass app, but can now use it from the Measure app.

1. Open the Measure app.

2. Tap Level at the bottom of the screen.

3. Position one of the edges of the phone along the surface you want to check. You can align the phone with either the long or short side of the phone, or even lay it flat on a surface.

4. If the edge or surface you’re measuring is level, the screen will turn green. If it’s off-level, you’ll see the level indicated with a line that divides the screen, and the angle will be displayed in the middle of the screen.

What Is the Measure App?

The Measure app uses augmented reality to let you draw lines that appear as a graphical overlay on top of what the camera is displaying on the screen. The Measure app turns these lines into actual measurements, which you can then photograph, giving you a record of the measured dimensions.