Slot Machine Odds: Payout Percentages Explained

Slot machine odds can be difficult to understand for any player who does not enjoy math. While the concepts are basic, they are not straightforward. Understanding slot machine payout percentages requires an illustration or two combined with a bit of math, so some gamblers avoid the subject altogether.

Today, we provide a quick how-to guide on how slot machine percentages work. This guide also gives tips for finding high-payout slot machines. Read through the article below and you’ll soon know the basics of slot machine payouts.




> > > > >


  • 200% Casino Bonus up to $5,000


  • 320% up to $3,000


  • 100% Match Bonus up to $1,000


  • 100% up to $250 Casino Bonus


  • 250% up to $2,500

Key Takeaways:

  • Understanding how slot machine odds and payouts work helps players find the best slot machines in land-based and online casinos. Learning about the house edge, RTP, variance, and volatility gives players an analysis of which are the best slots.
  • When you know how slot machine payout percentages work, you can compare gaming machines properly and find the best bets. The expected return is huge, but learning about volatility helps players find the best risks and rewards for their tastes.
  • Our guide provides tips for finding high-payout slot machines. Not only do we give names of the best online slots according to odds in 2024, but we also provide resources to help players find the best slot machines in the coming years.

How do slot machine payout percentages work?

We’ll explain why below, but players should know a couple of quick facts about slot machine odds. The higher a slot machine payout percentage is, the better is it for players. At the same time, the lower the house edge is, the better it is for you.

When a game designer creates a new slot, they must calculate the effect of every rule, betting option, and game feature on the expected return. Free spins and multipliers affect a slot machine’s odds, just like jackpot sizes do. Add it all up and you get the game’s payout percentage, also known as the return to player.

Slot Machine Odds

Slot machine odds work on probability. Each slot machine has a true random number generator (RNG). An RNG is simply a computer chip with an algorithm that accounts for every possible reel combination. Game designers program a certain probability to those reel combinations, matched to the bet sizes, coin denominations, and rules of that particular game.

Therefore, every possible result has a certain probability attached to it. These various probabilities add up to 100%. The RNG creates thousands of results per second based on the algorithm. When a player hits “Spin,” the RNG chooses the last result created as the outcome of the spin.

Video graphics represent that outcome on your screen, so the reels and symbols align according to the result chosen by the RNG. If the reel symbols align in a winning combination, then the slot machine awards the appropriate winning prize. The jackpot has the lowest odds of hitting on the machine, so players have a much lower chance of hitting the jackpot than any other result.

That’s how slot machine odds work, but how do slot machine percentages work exactly? Keep reading for the full details. But first, let’s answer a basic question.

Why is understanding slot machine odds and payouts so important?

Understanding slot machine odds and payouts helps you pick the best game. It’s the slot game equivalent of knowing basic strategy in blackjack. If you don’t understand how the math behind slot machine design works, you’re depending on simple luck.

At the least, you should know that a higher RTP helps you win more. You should also know that a lower house edge helps you have more winning sessions. Once you do, it comes down to finding reliable sources for the payout percentages and house edge of the top online slots.

Payout Percentages

Understanding payout percentages helps a player pick the online slot game with the best odds. Mathematical representations of slot machine odds are based on bets of $100. The return to player (RTP) statistic is based on the percentage of that $100 you would expect to see returned to you. If a game has a 98% RTP, you should expect to have $98 returned to you when you bet $100. The return would be in winnings from the game.

If the percentage is 93%, then you could expect to see $93 of every $100 wagered returned to you as winnings. That’s a full $5 less of every $100 wagered, so 98% is much better than 93%. Please remember the RTP stats are based on probability — not certainty.

That’s a good thing. If a game was certain to return 98% to you, that would mean you’d lose every single time. The difference between expected return and actual results is called variance. The measure of slot machine’s variance is called its volatility. High volatility slots have a wide range of variance in the results, meaning the 98% expected payback could be wildly off the mark — in your favor or against it.

Players who want a better chance at big winnings should pick a game with high volatility, but they should know this means they could lose a lot of money if they don’t win.

Positive Expectation Slot Machines

Readers might be wondering about slot machines with an RTP of higher than 100%. Such games are quite rare but do exist. If a slot has an RTP of 101%, that would mean you would expect to win $101 for every $100 wagered. Casinos wouldn’t stay in business for long if every game had these odds, so casinos don’t offer positive expectation slots very often. It happens.

For instance, if you’re playing a progressive slot machine that hasn’t paid out in a long time, the progressive jackpot may have grown to the point that it’s a positive expectation game. If the jackpot is larger than the odds of hitting the jackpot, then a progressive slot can be a positive expectation game.

Other instances might exist from time to time. If an online casino offers a lucrative slot bonus (either welcome bonus or reload bonus) and you play a game with a high return to the player — and you get 2% to 3% cashback for your credit card deposits — it’s possible your slots play would have a cumulative positive expectation. That would require several factors to align, so don’t expect an effective house edge of 100%+ often.

How to Find High Payout Slots

The cool thing about slot machines is you do all of the strategizing before the gaming session. Most slots don’t require skill or strategy. You don’t have to memorize tactics or make optimal plays. Instead, the key strategy is finding slots with the best odds possible. This is done before you sit down to play, so once you start hitting “Spin,” you can enjoy the game for what it is.

Therefore, the key factor is to find the highest payout slots.

Tips for Finding High Payout Slot Machines

  • Read Slot Machine Reviews: Read slot machine reviews to see what the game’s return to player percentage is. Only play the slots with the highest RTP.
  • Slot RTP Lists: Look at lists of online slots with the best RTPs. Several of our pages have such lists with the RTP stat posted next to them, so we recommend using Slots Guy as a resource.
  • Slot Player Forums: Visit player forums and find the threads that talk about the best slot odds. Networking with other players often helps.
  • Know Design Houses: Learn the software provider at online casinos. If you’ve researched Microgaming slots, then it pays to know which casino sites feature the best Microgaming slot games.
  • US Slot Providers: Be prepared to find US-friendly equivalents. Americans cannot find Microgaming slots without VPNs, so US players who play at offshore sites should study RealTime Gaming, Rival, Betsoft, and their competitors.
  • Updated Progressive Slot Stats: Visit websites that track progressive slot jackpots. Accurate trackers let you visit the online casinos with the best jackpots of the moment. Remember that jackpots vary from site to site, so pay attention to the jackpot and not just the slot machine’s name.


Smart slot players understand the odds before they play the game. Knowing the effect of payout percentages on your results means you play with your eyes wide open. Players will understand that the casino almost always has the advantage. Players will know they shouldn’t rely on slot machines to pay the bills, and chasing losses is never a good idea.

Ultimately, understanding slot machine odds and payouts leads to responsible gambling. You know what the casino operators and slot designers know. With that information, you can walk into brick-and-mortar casinos (or visit online slot casinos) knowing it’s for entertainment. Play with a reasonable bankroll, make reasonable bets based on slot odds, lock in winnings, avoid chasing losses, and walk away from the one-armed bandits once the fun is over.