For example on PokerStars if you're playingR$0.01/$0.02 NLHE or PLO then the rake is 3.50% of the pot, capped atR$0.30. If you're playing a bit higher than that, sayR$3/$6, then it's 5% of the pot capped atR$1.50 if there are 2-4 players at the table andR$3.50 if there are five or more players at the table.

It is generally 2.5% to 10% of the pot in each poker hand, up to a predetermined maximum amount.