Choose a bet size by counting how many bets your bankroll holds, not how many dollars. Your bet does not change the house edge, so it does not change what you lose per dollar on average. It changes how long the money lasts and how often a session ends early. A bankroll of 200 bets lasted a two-hour session in most of our simulations on low- and medium-volatility model slots; 50 bets usually did not. Try your own numbers in the session and bankroll calculator.
Think in bets per bankroll
Divide your bankroll by your bet. $200 at $1 is 200 bets. $200 at $0.50 is 400 bets. That number, not the dollar amount, decides how a session plays out, because a slot’s wins and losses come in multiples of the bet.
The calculator’s average figures scale directly with it: double the bets in your bankroll and the average session doubles in length. But averages hide the spread. The table below comes from 2,000 simulated sessions per cell on the calculator’s three model slots, all at 96% RTP and $1 a spin. Each cell shows how often a session was still going after 1,200 spins, which is two hours at 10 spins a minute.
| Bankroll | Low volatility | Medium volatility | High volatility |
|---|---|---|---|
| 50 bets | 27% | 14% | 5% |
| 100 bets | 59% | 28% | 10% |
| 200 bets | 95% | 59% | 22% |
| 500 bets | all of them | over 99% | 81% |
On a high-volatility game, even 200 bets saw fewer than one session in four through two hours. That is not a flaw in the game. It is what high volatility means: long losing stretches between rare large wins.
A simple way to set the bet
- Set the bankroll you are willing to lose in this session, and treat it as spent.
- Decide how long you want to play, then turn that into spins with your real pace. Two hours at 10 spins a minute is 1,200 spins.
- Pick the volatility you are playing, from the game’s information screen if it gives one.
- Choose the number of bets that gives a reasonable chance of lasting: on the table above, roughly 200 bets for low or medium volatility, and 500 or more for high.
- Divide. $200 for 400 bets means a 50-cent bet.
If the result is below the game’s minimum bet, the honest answer is a smaller session, a less volatile game or no session.
What bet size does not change
On many slots the RTP is the same at every bet level, so a $5 spin and a $0.50 spin give back the same share on average. Some games are built differently: a jackpot feature can depend on the bet level, and regulators allow RTP to vary slightly with bet size within limits. Michigan, for example, limits how far a game’s RTP may drop as the wager rises: by no more than one hundredth of a percentage point, unless all the drops together come to no more than half of one percent (Mich. Admin. Code R 432.633b). The game’s help screen describes any bet-dependent feature.
What a bigger bet always changes is the expected loss per spin and per hour. At 96% RTP, moving from $1 to $5 a spin lifts the average cost of an hour at 10 spins a minute from $24 to $120. Expected loss per hour shows the arithmetic.
Bet size and bonuses
If you are clearing a bonus, the terms may cap the bet while the bonus is active. Use the capped bet in the wagering calculator, because it decides how many spins the requirement takes. The bonus rules the calculator cannot see covers bet limits and the other terms that can void winnings.
Chasing is the bet-size mistake to avoid
Raising the bet after a loss to win it back is the fastest way to shorten a session. It does not change the odds of the next spin, which are independent of the last one, and it multiplies the cost of every spin that follows. Set the bet before you start and leave it there. The National Council on Problem Gambling lists chasing losses and feeling the need to bet more among the warning signs of a gambling problem; the responsible gambling page lists free, confidential help.
Common questions
What is a good bet size for a $100 slot bankroll?
It depends on how long you want to play and how volatile the game is. In our simulations, a bankroll of 200 bets lasted two hours of play at 10 spins a minute in about 95% of sessions on a low-volatility model and 59% on a medium one. For $100 that means about 50 cents a spin.
Do bigger bets improve the odds on slots?
No. On many games the RTP is the same at every bet size, so the house edge per dollar stays the same. A bigger bet only makes each spin cost more on average and makes your bankroll run out sooner.
Does betting the maximum unlock better payouts?
On some games the paytable or a jackpot feature depends on the bet level, so check the game's help screen. Where it does, the extra return has to be weighed against a much higher cost per spin and a shorter session.