Value bet calculator. Bet only when the price is wrong.
A bet has value when your read on the real chance beats the chance implied by the bookmaker's price. Enter the odds and your probability to see the expected value, your edge, and how much of your bankroll the Kelly criterion says that edge is worth.
The price vs your read
The decimal price on offer
Your estimate of the real chance (0–100)
Optional, sizes the Kelly stake
A bet has value when your estimated chance beats the chance baked into the price. Kelly then suggests how much of your bankroll that edge is worth staking.
Suggested stake (Kelly)
How it works
- 01
Read the price as a probability
Every decimal price implies a probability: 1 ÷ odds. A price of 2.00 implies a 50% chance. That's the bookmaker's view, before their margin.
- 02
Bring your own estimate
Estimate the real probability of the outcome from form, models, or research. If your number is higher than the price implies, the bet carries positive expected value over the long run.
- 03
Size it with Kelly
The Kelly criterion stakes more when the edge is bigger and the odds are longer. Half Kelly is the common default, it gives up a little growth for much smaller swings.
Bestbet is a research and price-discovery service, not a bookmaker. We don't accept wagers or hold funds. These calculators are informational, you place any bet yourself with your own bookmaker or exchange. You must be 18 or over. Please gamble responsibly. SA National Responsible Gambling helpline: 0800 006 008.