What is a payout percentage ?

A payout percentage is the percentage amount of winnings that a slot machine player can expect to win from the amount that is wagered. A typical slot machine will have a payout percentage of around 95% – meaning that for every $100 you stake, you can expect to get $95 back. The house will take the remaining $5. A payout percentage is always calculated and programmed into a slot machine in advance. Players are unaware of the percentage, but depending on the casino, typical payout percentages are between 82% and 98%. The machine may pay out a much higher or lower percentage over the first few rounds, but the longer a player plays, the closer they will come to the calculated payout figure. 

However, payout percentages are generally audited and verified by approved gambling monitoring board and this varies from country to country and sometimes differences can also be found even from state to state.