Polymarket Implied Probability Calculator

Convert any Polymarket market price into an implied probability — or go the other way and turn your probability estimate into a fair share price. Inputs update live; no submit button, no tracking.

Price → Implied Probability

Enter a value between 0.00 and 1.00 (e.g. 0.65 for a 65¢ YES share).
Implied Probability: 65.00% — the market's odds of YES resolving

Your Probability → Fair Price

Your private estimate of the true probability, 0–100%.
Fair Price: $0.7000 — what a YES share is worth at your probability
Example. If a market's YES side trades at 0.65, the implied probability is 65%. If you think the true chance is closer to 70%, the fair price is $0.70 — meaning the market is offering you a 5¢ edge per share if you're right.

How implied probability works

Polymarket prices are direct probabilities. A YES share that costs $0.65 pays out $1.00 if the event resolves YES, so buyers only profit if the real-world chance is above 65%. The price is the market's implied probability.

To turn a probability back into a price, just divide your percentage by 100. A 70% belief becomes a fair price of $0.70 per share.

When this calculator is useful

You'll want it any time you're comparing a market price to your own view — sizing a trade, checking whether a market has overreacted to news, or building a watchlist of mispriced markets. For deeper context on reading prices and order books, see our guide to how prediction market odds work.