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How is RTP calculated? Theoretical, actual, live tables
Theoretical RTP is a sum of probability times payout; actual RTP is wins over turnover. The UK regulator's worked example and tolerance table, read.
RTP is calculated two ways. Theoretical RTP multiplies each outcome’s probability by its return and sums the results; the game’s design fixes it. Actual RTP divides total wins by total turnover. Over short runs the two drift apart; the gap closes as games accumulate.
Evergreen explainer: the method comes from UK Gambling Commission operator guidance, last updated 25 January 2021, read by this desk on 31 October 2026: one regulator’s method, not a universal rule. Definition first: what RTP is and where live tables print it.
How is RTP calculated from the game’s design?
Multiply each outcome’s probability by its return per unit staked, stake included, and sum. A made-up ten-segment wheel where one segment returns 9 units and the rest nothing gives 1/10 x 9 = 0.90: 90% RTP, 10% house edge.
How is actual RTP calculated?
Wins divided by turnover. In the Commission’s worked example, a game designed at 91.68% takes £1,200,000 of turnover in a month and pays £1,085,000. 1,085,000 / 1,200,000 = 0.9042: an actual RTP of 90.42%, below design.
Is a game faulty if the figures differ?
Not on that alone. Volatility sets a tolerance that narrows with play. At a standard deviation of 5.6 the Commission prints:
| Games played | Range from the mean |
|---|---|
| 50,000 | +/- 4.90862 |
| 100,000 | +/- 3.47092 |
| 400,000 | +/- 1.73546 |
| 1,000,000 | +/- 1.09760 |
At 400,000 games the 91.68% game may measure 89.94% to 93.42%, this desk’s arithmetic. The table is set at 95% confidence, so a sound game can miss it about once in 20 tests; one miss does not confirm a fault.
How is RTP calculated for live casino games?
The design sum is unchanged. Monitoring differs. The live-dealer page says RTP monitoring focuses primarily on RNG software; wheels and cards sit under equipment and shuffling controls, though long-run result distributions remain worth measuring. Examples: Dream Catcher’s 54 segments and Crazy Time’s odds.
FAQ
How does RTP work?
RTP is a long-run average. The design fixes the theoretical figure; real play produces an actual figure that wanders around it. Over a few hundred rounds the gap can be wide; over hundreds of thousands it narrows. Monitoring works on volume, not sessions.
What is RTP and how does it work at online casinos?
It is the share of total stakes a game is designed to return; the rest is house edge. Online, every stake and win is recorded, so actual RTP is wins divided by turnover, checked against the designed figure within a volume-based tolerance.
How is RTP proven?
Two checks meet in the middle. A test lab works the theoretical figure from the paytable, by calculation or simulation. After launch, actual wins over turnover are measured against it. A result outside tolerance is a flag, not a verdict.
None of this covers a single session. Set the budget and the stop time before the first bet. 18+, and only where legally offered.
