Slot Bankroll and Session Calculator
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How to use this calculator
Pick what you want to work out. "How long will it last" takes your bankroll, bet per spin, the slot's RTP and how fast you play, and estimates how long the money should last on average and what it costs per hour. "Plan a session" works the other way: set how many hours you want to play and it shows the expected cost and number of spins. The hourly and per-spin costs are the theoretical average a slot of that RTP takes over time - the single most useful number for budgeting a session.
The numbers, explained
- RTP (return to player) - the share of all money wagered a slot pays back over millions of spins. A 96% slot keeps 4% on average.
- House edge - the flip side of RTP: 100% minus the RTP. This is what the game expects to keep.
- Spins per hour - your pace. A relaxed player does around 400, an average pace is roughly 600, and fast or auto-play can exceed 800.
- Expected cost - bet multiplied by the house edge, scaled to spins or hours. It is an average, not a prediction of any one session.
How it is calculated
It is the theoretical loss rate of a slot, which is fixed by its RTP, so the maths never needs updating.
- House edge
edge = 100% − RTP - Cost per spin
loss = bet × edge - Cost per hour
loss/hr = bet × spins per hour × edge - How long it lasts
hours = bankroll ÷ loss per hour
These figures describe the average over a very long run. They do not predict a single session, which is driven far more by variance than by the edge.
Variance is the real story on slots. The expected cost is an average measured over millions of spins; any single session can swing wildly around it. High-volatility games in particular can drain a bankroll long before the "average" time, or hit a bonus that extends it well past. Treat the result as a budgeting guide, never a guarantee - only ever play with money you can afford to lose, and set a time and loss limit before you start.
For information only. 19+ (18+ in AB, MB and QC). If gambling stops being fun, support is available through the Responsible Gambling Council. Please play responsibly.