actfap
Awesome Casino Treats For Amazing People
Free, genuinely useful tools and games for people who take gambling seriously — odds converters, bankroll math and more. No fluff, no sign-up.
Explore the tools↓odds
Odds Converter
Convert between decimal, fractional and American odds — and see the implied probability.
Odds Converter · try it
probability
Variance Simulator
See how far results swing over a session before the edge shows.
bankroll
Bankroll Calculator
Turn your bankroll, edge and risk tolerance into a safe stake.
probability
Expected Value Calculator
Odds plus your true probability, as expected value per bet.
odds
Parlay Calculator
Combine legs into one price and see the real payout.
probability
Poker Hand Odds
Win, tie and draw odds for any Hold'em matchup.
reference
Roulette Payouts
Every bet type, its payout and the house edge.
bankroll
Wagering Calculator
What a bonus really costs to clear at x35.
bankroll
Kelly Stake
The bet size that maximises long-run growth.
game
Martingale Simulator
Watch a doubling system meet the table limit.
game
Card Counter Trainer
Practise a running count against a live shoe.
About
Free casino & betting math, no sign-up
actfap is a small set of calculators and games for people who bet with an edge in mind — converting odds, sizing stakes, checking expected value and seeing how variance actually behaves. Everything runs in your browser.
- How do I convert odds to implied probability?
- Divide 1 by the decimal odds. 2.50 decimal is 1 / 2.50 = 0.40, a 40% implied chance. American +150 is 100 / (150 + 100) = 40%, and fractional 3/2 is 2 / (3 + 2) = 40% — every format describes the same probability.
- What is a positive expected value (+EV) bet?
- One where the price is better than the true probability, so you profit on average over many bets. If your fair estimate is 1.90 decimal and a book offers 2.10, that gap is roughly +10% expected value per unit staked.
- How much of my bankroll should I stake?
- Enough to survive variance. A flat 1–2% per bet is a common cautious rule. The Kelly criterion sizes the stake from your edge and the odds, and most people use a half- or quarter-Kelly fraction to smooth the swings.
- Does the Martingale system work?
- Not over time. Doubling your bet after every loss recovers small amounts until a losing streak pushes the next bet past the table limit or your bankroll — and then a single run wipes out every prior gain.
- Do these tools store or send my data?
- No. Every calculator and game runs entirely in your browser. Nothing you type is sent anywhere, and there is no account or sign-up.
- Are the tools free?
- Yes — all of them, with no account and no ads on the actfap tool pages.
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