PokéCoins are the currency of Pokémon GO. After earning or buying PokéCoins you can spend them on premium items like Raid Passes, Egg Incubators, Incenses or other useful items.
If you want to know how much money or PokéCoins very sucessfull players spend per day try this calculator NEW!.
How much PokéCoins do you earn in a gym?
Pokémon GO Trainers earn one PokéCoin for every 10 minutes their Pokémon has defended a gym.
10 Minutes are 1 coin, 20 Minutes are 2 coins, 30 Minutes are 3 coins and so on.
Keep mind that it is not possible to earn more then 50 PokéCoins per day.
Even if your Pokémon defended a gym for 20 hours you will receive only 50 coins for that day.
Keep also in mind that Pokémon GO players will only receive the eraned PokéCoins after their Pokémon returns from the gym and not while it is still defending (although you might already defended for 50 coins worth).
If you're still wondering why you should defend a gym once in a while to earn PokéCoins: The answer is because
you can spend them on helpful and cool premium items NEW!.