How to use Kelly Criterion Calculator
Enter win probability and win/loss payoff ratio. Read the suggested Kelly fraction and consider a fractional Kelly for crypto volatility.
Example: 55% win rate at 1.5-to-1 odds
Your strategy wins 55% of the time and pays 1.5-to-1. Your bankroll is $10,000 and you bet half-Kelly.
- Kelly fraction = (1.5 × 0.55 − 0.45) ÷ 1.5 = 25.00%
- Half-Kelly = 25.00% × 0.5 = 12.50%
- Stake = $10,000 × 12.50% = $1,250.00
Full Kelly says risk 25.00% of capital; half-Kelly risks 12.50% ($1,250.00), which cuts volatility a lot for a modest drop in growth. Kelly assumes your win rate is exact, which it never is.
Formula & methodology
Kelly f* = p − (1 − p)/b for odds b:1, win probability p (edge cases clamped).
Estimate Kelly bet size — then cut it down
Full Kelly assumes you know true odds. Crypto edges are noisy and fat-tailed, so half-Kelly or quarter-Kelly is common among practitioners who still use the formula at all.
CryptonicTools clamps pathological inputs so a bad probability does not explode the fraction. Treat the output as a ceiling for discussion, not a mandatory stake.
Not advice. Combine with position size and risk/reward tools before risking capital, and never size from a single backtest without stress tests or a written max-loss rule for the account.
Kelly pitfalls in crypto markets
Overestimating win rate is the usual failure mode. If your edge estimate is optimistic, Kelly over-bets and drawdowns deepen quickly.
Use drawdown-recovery math to see how painful a sequence of losses becomes when the fraction is too aggressive.
All CryptonicTools utilities are free, mobile-first, and require no account.