If you have an iPhone, that is.

Apple

The best way to measure something is still a tried-and-true tape measure. But if you don't have one on hand, your iPhone has a built-in tool that uses the camera (and, on Pro models, LiDAR) to get the job done.

If you didn't know that, well, you aren't alone. After releasing the tool in 2018, Apple hasn't exactly promoted the app. It merely sits in the Utilities folder, waiting (perhaps in vain) to be discovered.

Compatible iPhones

Filipe Espósito for Engadget

Unless your iPhone is truly ancient, you should have the Measure app. It came preinstalled on every model from the iPhone 6s and first-gen iPhone SE onward. If you deleted it at some point, you can redownload it from the App Store .

But Pro models get a better version. Apple added a LiDAR scanner starting with 2020's iPhone 12 Pro, and it's remained in all subsequent Pro-series iPhones. LiDAR fires invisible lasers to judge depth, making Measure more useful.…