Prediction Hunt

Trading tools

Prediction Market Calculators

Six calculators for the math the platforms do not show you: fees, fair odds with the vig removed, expected value, parlay payouts and take-home profit, built around Kalshi, Polymarket and PredictIt pricing.

  • KalshiPolymarketPredictItKalshi, Polymarket and PredictIt fee schedules
  • Free, no account needed
  • Instant, in-browser math

Market Fees

Calculate Kalshi fees, payout, net profit, and ROI, then compare taker, maker, profit, and category-based fees across prediction markets.

Vig & No-Vig

Calculate the vig (juice) baked into any market and find the true fair-value probability with the overround removed. Essential for spotting mispriced contracts.

Expected Value

Determine whether a trade has positive expected value given your estimated probability and the current market price. Know your edge before you enter.

Odds Converter

Convert instantly between American odds, decimal odds, and implied probability. Works for any prediction market, sportsbook, or exchange.

Parlay

Calculate combined odds, payouts, and ROI for multi-leg prediction market parlays. Enter each leg’s price and see your blended probability and return.

Net Profit

Estimate your actual take-home after platform fees and applicable taxes. See what you really make, not just what the contract pays out.

What are prediction market calculators?

Prediction market calculators help traders quickly do the math that platforms don't surface for you: true fees, expected value, fair odds stripped of vig, and real net profit after taxes. Without these tools, you're trading on incomplete information.

Each platform has a different fee structure. Kalshi charges transaction fees on both taker and maker sides that vary by contract price. PredictIt takes 10% of profits. Polymarket currently charges nothing. A position that looks identical across platforms can have meaningfully different economics once fees are factored in. The Market Fees calculator normalizes this so you're comparing apples to apples.

The Vig and Expected Value calculators solve a different problem: market prices contain a built-in house edge that distorts the implied probabilities. No-vig math strips that out so you can see what the market actually thinks the fair probability is, and whether there's a gap between that and your own estimate.

Frequently Asked Questions

Are these calculators free?

Yes, all tools on this page are completely free with no account required.

Which prediction market has the lowest fees?

The answer depends on contract price, order type, and market category. Kalshi’s maker fees are lower than taker fees, Polymarket fees vary by category, and PredictIt charges a percentage of winning profit. Use the Market Fees calculator for an apples-to-apples comparison.

What’s the difference between vig and no-vig odds?

Vig (short for vigorish, also called juice or overround) is the margin embedded in sportsbook odds when implied probabilities total more than 100%. No-vig odds normalize the outcomes back to 100%. For prediction-market exchanges, compare executable YES and NO prices rather than assuming midpoint prices contain sportsbook-style vig.

What is expected value in prediction markets?

Expected value (EV) is the average outcome of a bet if you made it many times. A positive EV trade means you’re getting better odds than the true probability warrants, which is your edge over time. EV = (probability of winning × profit) − (probability of losing × stake).

How do I use these tools for arbitrage?

Use the Market Fees calculator to find the true cost-adjusted price on each platform, then the Odds Converter to compare formats. The Vig calculator helps identify when market prices on opposite sides of the same event don’t add up to 100% after fees: that gap is your arb window.

Are the Prediction Hunt calculators available on Prediction.com?

Yes. Prediction Hunt is now Prediction.com, and every Prediction Hunt calculator is on this page: market fees, expected value, vig, odds converter, parlay and net profit. They are still free with no account required, and old predictionhunt.com links redirect here automatically.
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