Several months into this pandemic, you can no doubt already eyeball six feet/two meters with the best of them. But if you’re still having trouble — and happen to have an Android device handy — Google’s got you covered, I guess.
The latest project out of the company’s Experiments with Google collection, Sodar is a simple browser-based app that uses WebXR to offer a mobile augmented reality social distance. Visiting the site in Chrome on an Android handset will bring up the app. From there you’ll need to point your camera at the ground and move it around as the device recognizes the plane with a matrix of dots.
Move it up, and you’ll get a visual perimeter of two meters (that’s 6.6 feet for us imperial-unit-loving Americans) -- the CDC-recommended length to help curb the spread of COVID-19. The organization also handily lists it as "about two arms’ length." The app is probably more clever than it is useful at this point. Perhaps some day in the future, if smart glasses ever really take off. A big if, of course.
Meantime, holding a phone up to make sure you’re a proper distance away from your fellow human/disease vector is a bit less practical than good old-fashioned common sense.