Modern iPhones (specifically the Pro models from the iPhone 12 Pro onward) are equipped with a highly advanced piece of hardware known as a LiDAR (Light Detection and Ranging) scanner, built directly into the rear camera array. This sensor fires invisible pulses of light at objects and measures exactly how long it takes for the light to bounce back to the lens, allowing the iPhone to mathematically calculate exact distance and depth. Apple has ingeniously harnessed this hardware to allow you to instantly calculate a person’s exact physical height from the floor to the top of their head.
How to Use the Measurement Feature
You do not need to download a third-party application to use this hardware; Apple has built a dedicated utility specifically for this purpose.
- Locate and open the native Measure app on your iPhone. (It is installed by default, but if you deleted it, you can download it again for free from the App Store).
- Instruct the person you want to measure to stand up straight against a wall. (They can be sitting down, but standing is more accurate).
- Point the iPhone camera at the person.
- Physically step backward until the person’s entire body—from the absolute bottom of their feet to the very top of their head—is completely visible inside the camera viewfinder.
Reading the Results
You do not need to click anything or draw any lines. The software is entirely automatic.
- Within two or three seconds, the iPhone’s artificial intelligence will recognize that it is looking at a human being.
- The app will automatically draw a solid white line hovering horizontally just above the person’s head (or their hair, or their hat).
- A numerical value will appear just below the line, displaying their exact physical height in feet and inches (or centimeters, depending on your region settings).
- If you want to save the measurement for later, tap the large, circular white Shutter button in the bottom right corner of the screen to snap a photograph of the person with their height permanently overlaid on the image.