Polymarket Odds Calculator, Implied Probability & Expected Value (EV) Guide
Every Polymarket share is priced from 1¢ to 99¢ and pays out $1.00 if correct. Converting share price into implied probability is simple—knowing whether the true probability is higher than the market price is where fortunes are made. PolyEdge automates that math with Vision AI and on-chain whale data.
How Polymarket Implied Probability & Expected Value (+EV) Work
On Polymarket, a contract trading at 40¢ implies a 40% probability of occurring (before bid-ask spread and fees) and pays $1.00 if it wins—a gross profit of 60¢ per share (+150% return, or +150 in American odds / 2.50 in decimal odds).
To have positive Expected Value (+EV), your true win probability must exceed the effective entry price after fees: EV = (True Probability × $1.00) − Entry Price. PolyEdge’s Vision AI Market Analyzer calculates this gap automatically whenever you upload a contract screenshot.
- 20¢ share price = 20% implied odds (5.00x payout / +400 American odds)
- 50¢ share price = 50% implied odds (2.00x payout / +100 American odds)
- 80¢ share price = 80% implied odds (1.25x payout / -400 American odds)
- PolyEdge AI Analyzer compares market implied odds against AI-modeled fair probability in seconds
PolyEdge AI EV Analyzer vs. Manual Odds Calculators
Why automated probability modeling + whale flow beats a static calculator.
| Feature | PolyEdge (polyedge.us) | Static Web Calculators | Manual Mental Math |
|---|---|---|---|
| Converts share price to implied probability & payout multiple | Instant via Vision AI | Manual typing | Slow |
| Estimates true event probability from news & resolution rules | Included | You must guess | You must guess |
| Shows whether smart-money whales are buying at current odds | Included | Not available | Not available |
| AI Trading Coach for position sizing & bankroll discipline | Included | Not available | Not available |
How to Calculate Edge on Any Polymarket Bet in 30 Seconds
1. Screenshot Any Polymarket Contract
Drop the market card into the PolyEdge AI Analyzer.
2. Compare Market Implied Odds vs. AI Fair Probability
See immediately if the contract is underpriced (+EV) or overpriced.
3. Confirm Whale Consensus & Size Properly
Check the Wallet Tracker and ask the AI Trading Coach for optimal position sizing.
Frequently Asked Questions About Polymarket Odds & EV Calculator
How do you calculate implied probability on Polymarket?
A Polymarket share price in cents equals its approximate implied probability in percent (e.g., 35¢ = 35% implied probability). Because every winning share pays $1.00, your gross return on a winning trade is ($1.00 − Entry Price) / Entry Price.
How does PolyEdge calculate whether a Polymarket bet has positive EV?
PolyEdge’s Vision AI Market Analyzer reads the contract question, current ask price, and resolution criteria to estimate a fair probability range, then cross-checks whether high-win-rate whale wallets are accumulating the same outcome.