PuntersEdge Tools
Kelly Criterion Calculator Australia
Calculate the mathematically optimal stake size using the Kelly Criterion. Most bettors use half or quarter Kelly to reduce variance while preserving the long-run growth edge.
Results will appear here.
What is the Kelly Criterion?
The Kelly Criterion calculates the percentage of your bankroll to stake in order to maximise long-run bankroll growth. The formula is:
f = (b × p − q) ÷ b
Where b = decimal odds − 1, p = your win probability, q = 1 − p.
- A negative Kelly means no edge — do not bet.
- Full Kelly maximises growth but creates extreme variance.
- Half or Quarter Kelly reduces drawdown significantly with only a small cost to growth rate. Most professional bettors use fractional Kelly.
Kelly sizing depends entirely on the accuracy of your probability estimate. Overconfident estimates lead to overbetting. Use alongside the EV Calculator to validate your edge first.
Working with live odds?
This calculator is an educational guide. If you want the prices behind it, PuntersEdge publishes live odds from 15 Australian racing bookmakers as a REST/JSON API — next-to-go racing, runners, and best-odds comparison, with every response carrying its own age.
See API pricing · Developer docs · Get a free API key — 3,000 credits/month, no card.
18+ only. This calculator is for informational purposes only. Gambling can be addictive. Gambling Help: 1800 858 858.