Cluster Jewel Calculator
Optimize your Path of Exile passive tree by calculating the exact crafting probabilities and costs for your cluster jewels.
Crafting Estimates
Estimated Average Cost to hit target mods
Formula: Average Cost = (1 / (Target Weight / Total Weight)) × Cost per Attempt
Probability Success Curve
This chart shows the cumulative probability of hitting your target as you increase crafting attempts.
Figure 1: Cumulative success rate using the cluster jewel calculator logic.
| Jewel Size | Typical Total Weighting | Notable Weighting (Common) | Notable Weighting (Rare) |
|---|---|---|---|
| Large Cluster | 8,000 – 12,000 | 250 – 300 | 60 – 100 |
| Medium Cluster | 5,000 – 7,000 | 300 – 450 | 120 – 150 |
| Small Cluster | 3,000 – 5,000 | 500 – 600 | 250 – 300 |
What is a Cluster Jewel Calculator?
A cluster jewel calculator is an essential utility for players of complex ARPGs like Path of Exile who seek to optimize their passive skill tree through specialized jewels. These jewels allow players to expand their skill tree with custom passives, and a cluster jewel calculator helps determine the mathematical probability of rolling specific “notables” or modifiers on these items.
Using a cluster jewel calculator allows you to budget your currency effectively. Whether you are aiming for a 3-passive large cluster jewel or a specific efficiency small cluster, understanding the internal weightings is key. Many players use a cluster jewel calculator to decide whether it is cheaper to buy a finished jewel or craft it themselves using Alteration, Chaos, or Fossil orbs.
Cluster Jewel Calculator Formula and Mathematical Explanation
The math behind the cluster jewel calculator relies on a Bernoulli trial process. Each time you use a currency item, you are “rolling” against a total pool of possible modifiers. The probability depends on the sum of the weights of your target mods divided by the total sum of all possible mod weights for that item level and jewel base.
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Total Weight (Wtotal) | Sum of all possible mod weights | Units | 3,000 – 15,000 |
| Target Weight (Wtarget) | Weight of the specific notable | Units | 60 – 600 |
| Success Chance (P) | Probability of one attempt hitting | Percent | 0.5% – 15% |
| Unit Cost (C) | Cost of one crafting orb | Chaos Orbs | 0.1 – 5.0 |
The core formula used by the cluster jewel calculator is: Average Cost = (1 / (Wtarget / Wtotal)) × C. Furthermore, the cluster jewel calculator uses the cumulative distribution function 1 – (1 – P)n to determine the confidence interval for reaching success after n attempts.
Practical Examples (Real-World Use Cases)
Example 1: Large Physical Cluster Jewel
Suppose you are using the cluster jewel calculator to hit the “Master the Fundamentals” notable. If the total weighting for a Large Cluster is 10,000 and the notable weight is 300, your success chance is 3%. If Chaos Orbs cost 1 each, the cluster jewel calculator estimates an average cost of 33.3 Chaos Orbs. If you want a 95% certainty of hitting it, the cluster jewel calculator suggests planning for approximately 98 attempts.
Example 2: Small Mana Reserve Cluster Jewel
In this scenario, a player uses the cluster jewel calculator for a mana reservation notable with a weight of 500 in a pool of 4,000. The success chance is 12.5%. With an attempt cost of 0.5 Chaos (using Alterations), the cluster jewel calculator predicts an average cost of 4 Chaos Orbs. This helps the player realize that crafting is significantly cheaper than the market price of 20 Chaos.
How to Use This Cluster Jewel Calculator
Follow these steps to get the most accurate results from our cluster jewel calculator:
- Select Jewel Size: Choose between Large, Medium, or Small to set the baseline weights in the cluster jewel calculator.
- Enter Total Pool Weighting: Input the sum of all weights for the jewel’s mod pool. Higher item levels (iLvl 84+) often add more mods, increasing this number in the cluster jewel calculator.
- Set Target Weighting: Enter the weighting of the specific notables you desire. If you want any one of three notables, add their weights together for the cluster jewel calculator input.
- Input Unit Cost: Enter the price of the currency you are using (e.g., Chaos, Exalted, or fossils).
- Review Results: The cluster jewel calculator will instantly update the success chance, average cost, and confidence intervals.
Key Factors That Affect Cluster Jewel Calculator Results
- Item Level (iLvl): Higher levels unlock more mods, which can dilute the pool and increase the average cost shown by the cluster jewel calculator.
- Number of Passives: A 12-passive large jewel has different utility than an 8-passive one, though the cluster jewel calculator treats mod weightings similarly regardless of passive count.
- Notable Rarity: Some “tier 1” notables have significantly lower weighting, dramatically increasing the cost predicted by the cluster jewel calculator.
- Mod Conflicts: Some mods cannot roll together. A sophisticated cluster jewel calculator accounts for prefix/suffix limitations.
- Crafting Method: Using Fossils or Harvest crafting changes the weightings. This cluster jewel calculator assumes standard RNG weighting.
- Market Inflation: The unit cost of currency fluctuates, which directly impacts the “Total Cost” result in the cluster jewel calculator.
Frequently Asked Questions (FAQ)
Related Tools and Internal Resources
- Passive Skill Tree Optimization – Learn how to maximize your pathing efficiency.
- Jewel Socket Guide – A comprehensive look at where to place your jewels for maximum impact.
- Notable Passive Probabilities – A deep dive into mod weightings used in this cluster jewel calculator.
- Path of Exile Crafting Tools – Other essential calculators for endgame gear.
- Alt-Aug-Regal Methods – Mastering the most common way to craft clusters.
- Cluster Jewel Passive Layout – Understanding how notables are positioned on the jewel.