Whether you are trying to figure out if a new couch will fit in your living room, estimating the square footage for a painting project, or just moving into a new apartment, measuring a room with a traditional tape measure is tedious. It usually requires two people and a lot of floor crawling.
Fortunately, you already have a highly advanced spatial measurement tool in your pocket. Apple includes a built-in “Measure” app on modern iPhones that utilizes augmented reality (AR) and, on Pro models, a LiDAR scanner to accurately measure physical distances in the real world using just your camera.
This guide explains how to use your iPhone to measure the dimensions of a room.
How to Use the Measure App
The Measure app is pre-installed on all modern iPhones. If you deleted it previously, you can re-download it for free from the App Store.
- Ensure the room is well-lit. The camera needs to clearly see the textures of the floor and walls to track movement accurately.
- Open the Measure app on your iPhone.
- The app will immediately ask you to move your phone around. Slowly pan your camera across the floor and walls to allow the augmented reality engine to map your surroundings.
- A white circle with a dot in the center will appear on your screen. Point your camera so the dot rests exactly where the floor meets the corner of the wall.
- Tap the large Plus (+) button at the bottom of the screen to drop your starting pin.
- Slowly walk backward or pan the camera along the baseboard toward the next corner. You will see a yellow line extending from your starting pin, with a live measurement displaying on the screen.
- When the dot reaches the next corner, tap the Plus (+) button again to finish the line.
You now have an accurate measurement for the length of that wall. You can tap the measurement to copy it to your clipboard or take a screenshot to save it.
Pro Tip: Using LiDAR for Instant Room Measurement
If you own an iPhone Pro model (iPhone 12 Pro or newer) or an iPad Pro, your device is equipped with a LiDAR scanner. This laser radar maps rooms instantly and much more accurately than standard cameras.
When you open the Measure app in a room using a LiDAR-equipped device, you don’t even have to draw lines manually. The app will often automatically detect the edges of rectangular objects or even the floorplan of the room itself, allowing you to simply tap the suggested outlines to get instant, highly accurate measurements for the entire space.