Effective Spread Calculator

Understanding transaction costs in prediction markets is critical for profitability. The Effective Spread measures the true cost of trading by comparing your execution price to the mid-market price.

Calculate Your Costs

Mode

Units

Best Bid

Best Ask

Fills

Price

Quantity

Fees (Optional)

Fee Type

Effective Spread (Gross) -

Half Spread -

Execution Price (VWAP) -

Cost (One-way, All-in) -

Cost (Round-trip, All-in) -

Latest Guides

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Effective Spread Calculator: How to Use It

A step-by-step guide to measuring real execution costs in prediction markets using midquote, VWAP, and effective spread. Includes examples and common mistakes.

Read Guide →