How much mobile data does Pokémon Go use?
“Unfortunately the Pokémon Go app itself can’t really limit data usage much. Due to the free-roaming nature of the game and everything you can do with it, it’s hard to put a specific number on the amount of data Pokémon Go is going to use when you play.
How often you’re hitting PokéStops, going to gyms and battling will make a difference in your data usage. Walking around for about an hour actively playing Pokémon Go, we saw less than 20MB of mobile data usage. Tips for saving data when playing Pokémon Go Though the Pokémon Go app isn’t really using all that much data, there are a few things you can keep in mind to both potentially reduce the app’s data usage and also cut down on your overall data usage when you’re out playing. Keep your Wi-Fi on This one’s pretty basic, but is worth remembering if you’re in a city with lots of open Wi-Fi access points: leave your Wi-Fi on and hop on open networks to save some data while you’re out. If you’re going to be stationary for a few minutes, there’s little reason not to hop on that nearby Starbucks or McDonald’s free Wi-Fi. It’ll take a minute, but you’ll save a few megabytes”
At 20mb an hour, the data usage is fairly low from playing Pokemon Go. But if you become addicted to the game which many people are, playing for 2 hours per day, 7 days a week equates to 280mb. This in turn over a month becomes over 1gb. Just something to be wary of if your life gets possessed by Pokemon Go.