How to use the expected value of a bet calculator
Find the average profit or loss per bet from the chance of winning and the amounts won and lost. Enter probability of winning, amount won if you win, amount lost if you lose in the fields above; the expected value per bet, expected value as percent of stake are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “expected value of bet”, “is a bet worth it”, “gambling expected value”, “calculate expected value of a bet”, “find expected value per bet”.
Formula
Variables
- p — Probability of winning
- win — Amount won if you win ($)
- loss — Amount lost if you lose ($)
Worked example
With probability of winning = 0.45, amount won if you win = 100 $, amount lost if you lose = 100 $, the calculator gives expected value per bet ≈ -10 $; expected value as percent of stake ≈ -10 %.
Frequently asked questions
What is the expected value of a bet calculator used for?
Find the average profit or loss per bet from the chance of winning and the amounts won and lost. It helps with questions such as “expected value of bet”, “is a bet worth it”, “gambling expected value”.
What is the formula for the expected value of a bet calculation?
Expected value per bet ($) = p × win-(1-p) × loss. Expected value as percent of stake (%) = [Expected value per bet] / loss × 100. Here p is probability of winning, win is amount won if you win ($), loss is amount lost if you lose ($).
What inputs do I need for the expected value of a bet calculator?
You need probability of winning, amount won if you win in $, amount lost if you lose in $. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the expected value of a bet calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the expected value of a bet result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.