---
url: "https://predictiontoolkit.com/tools/eventarb/"
publisher: "PredictionToolkit"
dateModified: "2026-11-02"
---

[← Arbitrage](<https://predictiontoolkit.com/polymarket-arbitrage-tools/>) 

![EventArb logo](<https://predictiontoolkit.com/assets/logo-eventarb-56af34f21268.webp>)

Analytics

# EventArb: Multi-Leg Event-Contract Calculator

EventArb is a public event-contract calculator for comparing supported venues, including Polymarket. It makes capital, duration, binary/multiple-choice structure and fee-aware arithmetic explicit.

[**3.0**/ 5Editorial rating](<https://predictiontoolkit.com/tools/eventarb/#reviews>) [Editorial assessment](<https://predictiontoolkit.com/tools/eventarb/#reviews>) 

[Open the EventArb calculator](<https://eventarb.com/>) eventarb.com

**Available on:** Web

**Pricing:** The public calculator is free. It displays an optional donation link and free arbitrage-alert signup.

[Screenshots](<https://predictiontoolkit.com/tools/eventarb/#screenshots>) [Explore alternatives](<https://predictiontoolkit.com/tools/eventarb/#alternatives>) 

[Arbitrage](<https://predictiontoolkit.com/polymarket-arbitrage-tools/>) [Risk management](<https://predictiontoolkit.com/polymarket-risk-management-tools/>) 

## Screenshots and interface

Product preview1 / 2

The scenario input interface.

## What is EventArb?

Select venues and prices, add market legs and enter principal and days to completion. The interface provides sharing and How to Guide/The Math explanations, so assumptions can be inspected rather than reading a result alone.

The calculator neither places nor synchronizes orders. Similar names do not establish compatible settlement, and both prices and size can change before execution. The worked 45¢ YES/50¢ NO example is illustrative, not a live offer.

### Who it is for

-   Checking cross-venue arithmetic.
-   Comparing outcome structures.
-   Studying capital lockup time.

## Features and coverage

-   **Venues**
    
    Compare supported markets.
    
-   **Structure**
    
    Binary or multiple-choice outcomes.
    
-   **Legs**
    
    Add markets to a scenario.
    
-   **Principal**
    
    Set the capital amount.
    
-   **Duration**
    
    Enter days to completion.
    
-   **Fees**
    
    Calculator-described fee-inclusive spreads.
    
-   **Method**
    
    How to Guide and The Math.
    
-   **Sharing**
    
    Share a scenario through the interface.
    

## Workflows with EventArb

### Check a spread

Enter prices/capital and inspect fee assumptions.

### Compare capital use

Change duration with constant prices.

### Validate structure

Read every contract's resolution before treating legs as complementary.

## Pricing and total cost

The public calculator is free. It displays an optional donation link and free arbitrage-alert signup.

## Getting started

**Before you start:** Settlement differences can invalidate apparent complements.

1.  Select outcome structure.
2.  Enter days and capital.
3.  Choose venues and prices.
4.  Add legs.
5.  Calculate and read assumptions.

It does not place or synchronize orders.

## Useful links

### What to check

-   Settlement differences can invalidate apparent complements.
-   Prices and available size can change before execution.

A closer look

## Ratings & reviews

Editorial rating

**3.0**/ 5

0 user reviews

PredictionToolkit editorial

### Our take on EventArb

The free calculator exposes duration, capital and fees. It does not coordinate execution or establish equivalent contract rules.

Based on documented features, setup and access terms. [How we rate](<https://predictiontoolkit.com/methodology/>) 

### User reviews 0

The main score switches to user ratings after 5 published reviews.

**Be the first to share your experience**

A specific example helps the next person choose the right tool.

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Analytics**3.0**Editorial

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## Frequently asked questions about EventArb

### Can I add multiple markets?

Yes.

### Is duration included?

The form has days to completion.

### Will it execute both legs?

No execution flow is shown.

In this profile