Break-Even Win Rate Calculator

About this calculator

The break-even win rate is the implied probability baked into a set of betting odds — the win percentage at which a bettor neither gains nor loses money over the long run. For decimal odds, it is calculated simply as one divided by the decimal odds value; for example, odds of 2.50 imply a break-even win rate of forty percent, since a bookmaker offering those odds is pricing in roughly a forty percent chance of that outcome (before their margin, or “vig,” is factored in).

Sports bettors, professional handicappers, and arbitrage traders use this figure as the baseline against which they compare their own probability estimate for an outcome: if you believe the true win probability is higher than the break-even rate implied by the odds, the bet carries positive expected value; if it is lower, the odds do not compensate you enough for the risk.

This calculator takes the decimal odds you are being offered and returns the exact win rate you would need to hit to break even, so you can judge a bet’s value before staking money on it.