If you are shopping for furniture, hanging a picture frame, or trying to figure out if a new rug will fit in your living room, you do not need to hunt through your garage for a physical tape measure. Every modern iPhone comes with a built-in Augmented Reality (AR) tool called the Measure app. By using your phone’s camera and internal sensors, it can measure physical objects with surprising accuracy.
How to Measure an Object or Space
- Open the Measure app (it comes pre-installed on your iPhone. If you deleted it, you can redownload it for free from the App Store).
- The app will ask you to “Move iPhone to start.” Move your phone around the space slowly so the camera can calibrate and understand the room’s layout.
- Look at your screen. You will see a white circle with a dot in the middle. This is your cursor.
- Point the dot at the starting point of what you want to measure (e.g., the corner of a table).
- Tap the + (Plus) button at the bottom of the screen to lock in the starting point.
- Slowly pan your iPhone across the object until the dot reaches the ending point. You will see a dotted yellow line drawing across the screen with the measurement in real-time.
- Tap the + (Plus) button again to lock in the ending point.
The final measurement will hover over the object on your screen. You can tap the measurement number to see it converted into inches or centimeters, or tap the white shutter button in the bottom right corner to take a screenshot of the measurement to save for later.
How to Measure Rectangular Objects Automatically
If you are measuring a perfectly square or rectangular object (like a painting, a window, or a piece of paper), the Measure app can do the work for you instantly.
- Point your iPhone camera at the object.
- The app will automatically detect the edges of the rectangle and draw a yellow box around it.
- Tap the + (Plus) button.
- The app will instantly display the exact length and width of the object.
How to Measure a Person’s Height
If you have an iPhone Pro or iPad Pro equipped with a LiDAR scanner (iPhone 12 Pro and newer), the Measure app includes a hidden party trick: it can instantly measure a person’s height.
- Open the Measure app and point the camera at a person.
- Ensure their entire body (from head to toe) is visible on the screen.
- After a second, a line will automatically appear at the top of the person’s head (or hat/hair) displaying their exact height.
Conclusion
While a physical tape measure is still best for exact construction work, the iPhone’s Measure app is an incredibly handy, always-in-your-pocket tool for quick, everyday estimations and interior design planning.