Expected session cost by RTP

Formula

total wagered = bet × spins per minute × minutes
expected cost = total wagered × (1 − RTP)

What these numbers do not tell you

Volatility decides how far actual results can stray from the average. A high-volatility slot can burn through a budget much faster than this estimate before paying out anything big, or without ever doing so. Treat these figures as a starting point for budgeting, not a promise.

Each game's RTP is usually shown on its game information screen. Check it there after logging in through slotkaki.shop.

Slot sessions worked through step by step

Example 1: the calculator's default values

RM 1 a spin, 10 spins a minute, 60 minutes, RTP 96%. Total wagered = 1 × 10 × 60 = RM 600. Expected cost = 600 × (1 − 0.96) = RM 24.00. As the session lasts exactly an hour, the cost per hour is also RM 24.00.

Example 2: small stakes, a 45-minute session

RM 0.40 a spin, 12 spins a minute, 45 minutes, RTP 96.5%. Total wagered = 0.40 × 12 × 45 = RM 216. Expected cost = 216 × 0.035 = RM 7.56. Cost per hour = 7.56 ÷ 45 × 60 = RM 10.08.

Example 3: 94% against 97% RTP

RM 2 a spin at 8 spins a minute for 30 minutes comes to RM 480 wagered. At 94% RTP the expected cost is RM 28.80; at 97% it is RM 14.40. Three percentage points double the average cost of the same session. That is why the RTP is worth checking before you pick a game, even though both games still cost money on average rather than return it.

What each result box is telling you

• Total wagered is the sum of every bet, not the cash you need to bring. Small wins get bet again, so RM 600 can pass through a much smaller balance.
• Average expected cost is the share of that total that stays with the house as a long-run average. It is not an amount you are certain to lose today.
• Cost per hour turns the cost into a rate, so a 20-minute session and a three-hour one can be compared fairly. With a duration of 0 the box shows "–".

Variance: why short sessions swing so far

Variance measures how widely real results spread around the average. RTP is worked out over millions of spins. Your session might be 600 spins, and over a sample that small the range of possible results is very wide.

Think of a coin. Toss it 10 times and getting 7 or more heads is nothing unusual: the chance is about 17%. Toss it 1,000 times and 700 or more heads practically never happens. The average only settles down when the number of tries is very large.

Slots behave the same way, only more so, because their payouts are lumpy. As an illustration, a single 200x hit on a RM 1 spin is worth RM 200 and can turn a losing session into a winning one. Without a hit like that, the same session can lose far more than RM 24. Both outcomes fit perfectly well with 96% RTP. Variance cannot be predicted or steered. It simply means one session can finish a long way from the average, in either direction.

Input slips that throw the estimate off

• RTP typed as a decimal. The calculator wants 96, not 0.96. Enter 0.96 and the expected cost comes out at almost the entire amount wagered.
• Too few spins per minute. With autoplay or turbo mode the pace can be well above 10 a minute. Count your own spins for one minute and use that figure.
• The budget entered as the bet. The first field is the stake per spin, not the money set aside for the session.
• An RTP from somewhere else. Some games exist in several RTP versions. Use the figure on the information screen of the game you actually open.
• Stakes changed mid-session. If you raise the bet, run the numbers again at the new size. Expected cost rises in step with the stake.

Setting the expected cost against your session limit

Put the expected cost next to the session limit from the monthly budget planner. If the limit is RM 50 and the planned session has an expected cost of RM 24, nearly half the limit is the average price of the entertainment, and the real result can be worse. If the expected cost already comes close to the limit, lower the stake or shorten the session. Both cut the total wagered directly.

The play session timer helps a 60-minute session stay at 60 minutes. To compare costs across slots, baccarat, roulette and other table games, use the house edge calculator. Terms such as variance and expected value are defined in the glossary of probability terms.

Frequently asked questions