This calculator turns a monthly gambling budget into session limits and shows what your play is expected to cost. It rests on one formula: expected loss = total wagered × house edge. It cannot predict a win or a loss, and no budgeting method changes the house edge. What it can do is show you the price of an evening’s play before you spend it.
How the Bankroll Calculator works
Four steps, all done in your browser. Nothing you type is stored or sent anywhere.
- Session budget = monthly budget ÷ number of sessions.
- House edge = 100% minus the game’s RTP (return to player).
- Expected loss per hour = bet size × bets per hour × house edge.
- Time your session budget lasts, on average = session budget ÷ expected loss per hour.
Worked example
Say your monthly budget is $200, split into four sessions of $50. You play a slot with a 96% RTP, so the house edge is 4%. You bet $1 a spin and play about 600 spins an hour (an assumption; use your own speed).
- You wager $600 an hour.
- The expected loss is $600 × 4% = $24 an hour.
- A $50 session budget lasts about 2 hours and 5 minutes on average.
Drop the bet to $0.25 a spin and the expected loss falls to $6 an hour. Lower stakes stretch your entertainment time. They do not change the house edge.
What do the results mean?
Every figure is an average over a very large number of bets. In a single session you can lose the budget in minutes or finish ahead, especially on high-volatility games. The calculator shows the expected cost, not what will happen tonight. The “weekly deposit limit” line is your monthly budget spread across the weeks of a month, a number you can enter in your casino account’s deposit limit settings.
Frequently asked questions
What is a bankroll?
A bankroll is the money you have set aside for gambling, separate from rent, bills, savings and debt repayments. If losing it would cause a problem, it is not a bankroll.
How much should I bet per spin or hand?
A common comfort guideline is a bet small enough that your session budget covers at least 100 to 200 bets. That is a guideline for making the money last, not a strategy for winning. The calculator flags when your session budget covers fewer bets than that.
Where do I find a game’s RTP?
Most slots show it in the game’s info or help screen, and many casinos list it in the game details. Some games offer several RTP settings, so check the one on the game you are actually playing. For an explanation of RTP, volatility and house edge, read RTP, Volatility and House Edge Explained.
Does it work for roulette and blackjack?
Yes, with the right RTP and speed. The game type menu fills in typical values: 97.3% for single-zero roulette and 94.74% for double-zero roulette (both follow from the wheel: one or two losing slots in 37 or 38), and about 99.5% for blackjack played with basic strategy on typical rules. The blackjack figure varies with the rules and how well you play, and the bets-per-hour figures are assumptions, so change them to match your own play.
Can bankroll management help me win?
No. Betting systems change the pattern of wins and losses, not the expected loss per amount wagered. Bankroll management controls how much you spend and how long the money lasts. For the full picture, read Bankroll Management Basics.
Does the calculator include bonuses?
No. Bonus wagering requirements can raise the amount you must bet, which changes the cost. See How Wagering Requirements Work.
This tool is for adults aged 18 and over and is an educational estimate, not advice. If gambling is causing you problems, use your casino’s deposit limits and self-exclusion tools and speak to a local support service. In Great Britain, the National Gambling Helpline is 0808 8020 133.