Prediction markets like Polymarket, Kalshi, and PredictIt operate differently than traditional sportsbooks. Instead of offering odds (like +150 or 2.50), they sell “Event Contracts” priced in cents (e.g., 40¢ or $0.40).
For a traditional bettor, this can be confusing. Is buying a “Yes” share at 60¢ better value than betting at -150 odds? Our Prediction Market Odds Converter bridges this gap. It instantly translates share prices into American and Decimal odds, calculates the implied probability, and simulates your potential returns if the contract hits $1.00.
Prediction Market Calc
Kalshi / PolymarketHow to Use the Calculator
This tool works as a two-way translator between financial trading and sports betting math. Here is how to use it:
- Enter Share Price: If you are looking at a market on Polymarket (e.g., “Fed Interest Rate Cut”), enter the current price in cents (e.g., 65).
- Note: You can also type in the Odds (Decimal or American) to see what the equivalent Share Price would be.
- Analyze the Conversion:
- Decimal/American Odds: See the equivalent betting line. For example, 65¢ equals roughly -185 (American) or 1.54 (Decimal).
- Inverse Price: The calculator automatically tells you the price of the opposing side (“No”). If “Yes” is 65¢, “No” is 35¢.
- Simulate Investment: Enter your budget (e.g., $500) into the Investment Simulator. The tool will calculate exactly how many shares you can buy and your total net profit if the event occurs (contracts settle at $1.00).
Understanding the Math: Cents vs. Odds
In prediction markets, every contract pays out exactly $1.00 if the event happens and $0.00 if it does not. Therefore, the price is simply the Implied Probability.
Example 1: The Favorite (High Price)
Market: “Will it rain tomorrow?” trades at 75¢.
- The Math: You pay $0.75 to win $1.00. This is a 25¢ profit.
- Odds Equivalent: This is a 75% probability. In betting terms, this is 1.33 Decimal or -300 American.
- Investment: Investing $100 buys you 133.3 shares. If it rains, you get back $133.30 (Profit: $33.30).
Example 2: The Longshot (Low Price)
Market: “Candidate B wins the election” trades at 12¢.
- The Math: You pay $0.12 to win $1.00. This is an 88¢ profit.
- Odds Equivalent: This is a 12% probability. In betting terms, this is 8.33 Decimal or +733 American.
- Investment: Investing $100 buys you 833.3 shares. If they win, you get back $833.30 (Profit: $733.30).
Frequently Asked Questions (FAQ)
What is the difference between Polymarket and Kalshi?
Mathematically, they are identical: both use binary contracts that settle at $1.00 (or equivalent). Polymarket is crypto-based (USDC) and decentralized, while Kalshi is a US-regulated exchange dealing in fiat currency. This calculator works perfectly for both.
Why do the “Yes” and “No” prices not always add up to $1.00?
In a perfectly efficient market without fees, Yes + No should equal $1.00 (100%). However, if Yes is 60¢ and No is 42¢ (Total $1.02), the extra 2¢ represents the spread or market inefficiency. You can use our Margin Calculator to see the “vig” on these markets.
How do I calculate profit?
The formula is simple: (1.00 - Share Price) / Share Price = ROI. Or simply subtract your entry price from $1.00. If you buy at 40¢, your potential profit is 60¢ per share.