Kelly calculator v1.1
About the project
What is the Kelly calculator?
This project is a web tool for calculating the Kelly fraction for investments and bets. It connects win probabilities and odds and shows how the chosen fraction affects capital.
The dashboard demonstrates the formula with a Monte Carlo simulation. This makes it possible to compare how full Kelly, fractional Kelly and overbetting affect a portfolio and the risk of ruin.
Features
What can the dashboard do?
- Custom inputs: Enter win probability, win and loss odds and starting capital.
- Kelly calculation: The mathematical Kelly fraction is calculated immediately.
- Interactive simulation: JavaScript generates random gaming and investment paths over hundreds of iterations.
- Simulation chart: A chart shows wealth growth and the difference between the Kelly fraction and overbetting.
- Ruin warning: An indicator makes the risk of persistently negative stakes visible.
- Kelly explanation: The formula is explained using the entered parameters.
- Responsive design: The interface runs smoothly on desktop and mobile.
- Code optimisation: Vanilla JavaScript without large external libraries keeps loading times short.
Screenshots
Inside the dashboard
Kelly dashboard v1.1
Interactive simulation interface
Reflection
What I learned
I applied probability and risk management in practice. The simulation had to display hundreds of runs without noticeable delay.
The sliders and curves show why overbetting can lead to ruin over the long term, even when expected value remains positive.