House Edge Calculator
House edge = 100% − RTP, for any game.
How to read a slot’s house edge
The house edge is the share of every stake that a slot is designed to keep over the long run. It is the flip side of RTP, and it is the clearest way to see what a game costs you. The house edge calculator does the sum in a second.
The formula
It could not be simpler: house edge = 100% − RTP. A slot with 96.5% RTP has a 3.5% house edge. A slot with 94% RTP has a 6% edge. Enter an RTP and the calculator returns the edge, plus the average cost per £100 or £1,000 staked.
Worked examples
- 96.5% RTP: edge 3.5%. On £1,000 staked, the average cost is £35.
- 94% RTP: edge 6%. On £1,000 staked, the average cost is £60.
That £25 gap on the same £1,000 shows why a few points of RTP matter, especially over many spins. The house edge applies to the total you stake, not to your starting balance. Because winnings are re-staked, a £50 budget can generate far more than £50 of total stakes.
What the edge cannot tell you
The house edge is an average across a huge number of spins. It does not predict your next spin, your session or your week. It also says nothing about volatility, which decides how bumpy the ride is. Two slots with a 4% edge can feel completely different, and you can read how in our guides to low-volatility slots and high-volatility slots.
To see how the edge turns into an hourly cost, use the expected loss calculator. To check any slot’s RTP, look at the game page or the top high-RTP slots list, and for the plain-English meaning of RTP, try the RTP calculator. Gambling is entertainment, never a way to make money. 18+ only.
Questions people ask
What is the house edge on slots?
It is the percentage of total stakes a slot keeps on average over the long run, calculated as 100% minus RTP. A 96% RTP slot has a 4% house edge, meaning £4 of every £100 staked is kept on average. You can find a game’s RTP on its page, and subtracting it from 100 gives the edge for that slot.
How do you calculate the house edge from RTP?
Subtract the RTP from 100. If RTP is 96.5%, the house edge is 3.5%. Multiply the edge by your total stakes to get the average cost: 3.5% of £1,000 is £35. The house edge calculator does this instantly and shows the average cost for different amounts staked.
Is a lower house edge always better?
For average cost, yes. A lower edge means a smaller expected loss per £ staked. It does not change volatility or guarantee a result, so a low edge slot can still lose in a given session. Choose by the experience you want as well as the edge, and always play within a budget you can afford to lose.
What is the average house edge of online slots?
It varies by game and setting. Many slots are built around a 4% edge (96% RTP), while some are lower and some higher. Check each game’s figure, or rank them with top high-RTP slots. The figure is an average over millions of spins, so any one session can end well above or below it.
Does the house edge mean I will lose 4% of my money?
No. It applies to the total amount you stake, including re-staked winnings, over a very long run. Your real result in one session is much more uneven and can be a win or a loss. Use the calculator to turn the percentage into pounds for your own stake and number of spins.