Many slots gamblers, including those who’ve been playing offline and online slots for real money for years, might not understand what the terms RTP and volatility mean. While these terms might not be too concerning to you if you’re just looking to spin the reels and have some fun, these two elements can and do dramatically affect your slot experience when you play at a casino online or offline.
If you’d like to learn about the role of RTP and volatility in slots, read on to discover everything you need to know about each of these slot elements and how they are connected.
Everything You Need To Know About RTP
While you can still have a great time playing slots without ever knowing what RTP is, the principle is a critical element of the online slot experience.
What Is RTP?
What is RTP in slots? RTP, or return to player, is a term that’s used to indicate to slots gamblers what the average payout is for a particular slot, and it is shown as a percentage.
For example, a slot might have an RTP of 95%. This means that for every dollar that is paid into the game, the game will return 95 cents. This doesn’t mean that you will receive 95 cents back, but that over a long period of time, 95 cents to the dollar is what will be paid out to all players. While some slots players will receive more and others will receive less, it’ll average out to 95% in the long run.
The average RTP for slots is 96%, but slots with the best odds have an RTP as high as 99%, while slots with the worst odds can have an RTP of 90% or lower. Another factor to keep in mind is whether you’re playing jackpot slots or not. Jackpot slots take the jackpot payout into account for their RTP, which means that the RTP is likely to be much lower without the jackpot prize factored in.
How Is RTP Calculated?
Actual RTP is calculated by taking the total amount spent on a game and dividing it by the total amount won by players. However, this may differ from the game’s official RTP, which is determined by the slot developer. This is for two reasons.
Firstly, it’s important to note that RTP isn’t a number that can be applied to a short period of time or a small number of games; it is typically calculated over tens of thousands or even hundreds of thousands of games.
Secondly, the actual RTP may change slightly from month to month due to the game’s volatility. You can learn more about volatility below.
How To Check the RTP of an Online Slot
When you play at an online casino, the RTP for a game will typically be available on the game’s page. If the casino doesn’t display the RTP before you start playing, you can also find it by checking the slot’s help files in the game itself. If no RTP is listed under the game’s help files, you can also check online reviews or the game developer’s website for relevant information.
Everything You Need To Know About Volatility

Volatility is another important element that can influence your enjoyment of online slots. Here’s all the information on volatility and how it affects your slot gaming experience.
What Is Volatility?
What is slot volatility? Slot volatility, also known as variance, is the frequency and size of payouts that you can expect from a slot. Volatility is typically divided into three categories:
- Low: Low volatility means that a game will offer more frequent but smaller payouts.
- Medium: Medium volatility means that a game offers a mix of smaller, more frequent payouts and larger, less frequent payouts.
- High: High volatility means that a game will offer less frequent but larger payouts.
Just like RTP, volatility is calculated over thousands of games, meaning that the frequency or size of payouts can shift quite dramatically during a single session. For example, even when playing a low volatility slot for multiple spins, you may hit a bad run of luck and not land a single winning combination.
How Is Slot Volatility Calculated?
To find out whether the volatility of a game is low, medium, or high, or somewhere between these categories, games are tested over long periods of time, just like they would be for RTP. A formula is then used to calculate what is called the volatility index, or VI. Numbers closer to 0 are considered low-volatility games, while higher numbers are considered high-volatility games. The exact numbers are never released to the public, but you can use the low, medium, or high volatility categories to guide your decision on which slot game to play.
How To Check Slot Volatility of an Online Slot

Just like RTP, slot volatility is often displayed on the game page at an online casino or in the game’s help files. If the information isn’t included in either of these locations, you can do an online search to confirm the volatility through online reviews or the game developer’s site.
How Are RTP and Volatility Connected in Online Slots?
Ultimately, both RTP and volatility can affect the enjoyment you have when playing an online slot, so be careful how you choose online slot games. The most important thing to remember when it comes to RTP and volatility is that RTP helps you understand the potential of payouts in the long term, while volatility helps you understand payouts in the short term.