๐ŸŽฐProbability Game EV Calculator

Enter entry fee, prize, and win probability to calculate expected value and ROI

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How to Use the Probability Game EV Calculator

Enter the entry fee, prize amount, and win probability to see the expected value (EV), ROI, and break-even probability. A positive EV means the game is mathematically profitable over the long run. A negative EV means you expect to lose money on average.

Formula Guide

Expected Value = Prize ร— (Win% รท 100) โˆ’ Entry Fee. ROI = EV รท Entry Fee ร— 100. Break-Even Probability = Entry Fee รท Prize ร— 100 โ€” this is the minimum win rate needed to recover your cost. If the actual win probability exceeds this threshold, you have a mathematical edge.

Frequently Asked Questions

Does positive EV always mean I'll profit?

Over many repetitions, yes โ€” the average outcome will be positive. But any single play can still lose due to randomness.

Can I use this for lotteries?

Yes. Enter the ticket price as the fee, the jackpot as the prize, and the stated odds. Most lotteries have negative EV.

What if there are multiple prize tiers?

Calculate the EV contribution of each tier separately, then add them all up for the total expected value.