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Overview Getting Started

Last Updated: 3/10/2026

Overview & Getting Started

The TFT Rolling Odds Calculator is a web-based probability calculator designed to help Teamfight Tactics (TFT) players make informed decisions when rolling for specific units. Using advanced Markov Chain mathematics, it calculates the exact probability of finding your desired champions based on your current game state.

What is This Calculator?

In TFT, players spend gold to “roll” their shop, hoping to find specific units to complete their team composition. This calculator answers the critical question: “What are my chances of finding X copies of a unit if I spend Y gold?”

The calculator takes into account:

  • Your current level (affects shop odds)
  • The cost tier of the unit you’re looking for
  • How many copies are already taken from the shared pool
  • How much gold you plan to spend
  • Headliner mechanics (special featured units)

Live Demo

🎮 Try it now: TFT Rolling Odds Calculator 

Quick Start Guide

Basic Usage

  1. Set your desired unit cost (1-5 stars)
  2. Set your current level (1-11)
  3. Enter how many copies of that specific unit are already out of the pool
  4. Enter how many units of the same cost are out of the pool
  5. Enter how much gold you want to spend rolling
  6. View the probability chart showing your chances

Example Scenario

Let’s say you’re level 7, looking for a 4-cost carry:

Desired unit cost: 4
Current Level: 7
Copies already out: 3
Same-cost units out: 25
Gold to spend: 40

The calculator will show you a bar chart with probabilities like:

  • 65% chance to find at least 1 copy
  • 35% chance to find at least 2 copies
  • 12% chance to find at least 3 copies

Key Features

Accurate Probability Calculations

  • Uses Markov Chain mathematics for precise results
  • Accounts for the shared unit pool system
  • Includes headliner probability calculations

Visual Results

  • Interactive bar chart powered by Chart.js
  • Shows cumulative probabilities (“at least X units”)
  • Easy-to-read percentage format

Up-to-Date Game Data

  • Currently configured for TFT Set 10
  • Pool sizes: 22/20/17/10/9 for each cost tier
  • Distinct champions: 13/13/13/13/8 per cost
  • Level-based shop odds included

When to Use This Calculator

Before Rolling Down

Use the calculator during planning phase to decide:

  • Is it worth rolling now or waiting for higher level?
  • How much gold should I commit to finding this unit?
  • Should I pivot to a different comp based on the odds?

Competitive Analysis

Understand the math behind:

  • Why high-rolling at certain levels is more effective
  • How contested units affect your odds
  • When to commit to 3-starring units

Learning Tool

Great for:

  • Understanding TFT’s probability mechanics
  • Teaching players about expected value
  • Analyzing different rolling strategies

Understanding the Math

The calculator uses Markov Chains to model the rolling process. Each shop is a state transition, and the calculator computes the probability of reaching different states (0 units found, 1 unit found, 2 units found, etc.) after a certain number of shops.

For a detailed explanation of the mathematics, see the Mathematical Background article.

Current Version: Set 10

Last updated: November 26, 2023

Set 10 Configuration:

  • Bag sizes: 22/20/17/10/9 for costs 1-5
  • Distinct champions: 13/13/13/13/8 for costs 1-5
  • Headliner mechanics included

Note: When new TFT sets are released, the calculator needs to be updated with new pool sizes and champion counts. See the Development Guide for how to update these values.

Browser Requirements

The calculator works in all modern browsers:

  • ✅ Chrome/Edge (recommended)
  • ✅ Firefox
  • ✅ Safari
  • ✅ Mobile browsers

No installation required - it runs entirely in your browser!

Next Steps

Credits

Originally created by wongkj12 , maintained by the community.

GitHub Repository: TFT-Rolling-Odds-Calculator 

How To Use The CalculatorTechnical Implementation