Chromecast's new screen casting feature has a lot of us very excited, and understandably so: you can now... Android... on a gigantic screen, at the push of a button. Or touch, I guess. Anyway, screen casting is pretty awesome, but there's one thing that's bugging some people: latency. Now, if you're sitting right next to your router, and your Chromecast is also sitting right next to your router, the latency on screen casting generally isn't that bad (probably less than 100ms).
[This One Simple Trick] Calculating Your Chromecast Screen Casting Latency Is As Easy As Pulling Out Your Camera was written by the awesome team at Android Police.