Polymarket probability & EV calculator

Convert prices to implied odds, subtract a fee haircut, and compare to your probability. Free educational tool—not financial advice.

Implied probability
42.0%
Break-even after fees
42.4%
Estimated edge
7.6 pp
Approx. EV (Yes share buy)
$19.05

Educational math only—not financial advice. Ignores spread, slippage, and venue-specific fee curves. Pair with Polifly's AI analyzer for structured research.

How to use this

Prediction market prices approximate probabilities before frictions. Your edge is whether your calibrated probability beats break-even after fees and spread.

Always read resolution rules first. Then stress-test with the Polifly AI market analyzer.

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