How to Use the Item Upgrade Expected Cost Calculator
Enhancement systems let you upgrade items by attempting upgrades that consume materials, with each attempt having a fixed success rate. This calculator uses the geometric distribution formula to compute the average number of attempts and total material cost needed to reach your target enhancement level.
How the Calculation Works
The average attempts per level equals 100 divided by the success rate. For example, at 30% success rate you need an average of 3.33 attempts per level. For 10 levels that is 33.3 total attempts. At $5 per attempt, the expected total cost is about $167.
Tips to Reduce Upgrade Costs
Lower success rates mean higher variance — actual cost can be much higher or lower than the expected value. Using success rate buff items or taking advantage of events that boost success rates can dramatically lower expected costs.
Frequently Asked Questions
Yes. Expected cost is an average. Actual cost varies by luck and can be higher or lower.
Run the calculator separately for each section and sum the expected costs.
Yes. It assumes materials are consumed on each failed attempt. Check your game's rules.