Loot Gear Level Probability Calculator
Enter the base chance per attempt, between 0 and 100.
Enter the total number of loot attempts you plan to make.
Select Yes if the game increases drop rates after a set number of failed attempts.
How to Use This Tool
Enter the base drop rate percentage for your target gear level, then input the total number of pulls, rolls, or attempts you plan to make. Select whether the game uses a pity system, and if so, fill in the pity threshold and increased drop rate. Choose the probability type you want to calculate from the dropdown, then click Calculate to see detailed results.
Use the Reset button to clear all inputs and start a new calculation. Click the Copy Results button to copy all result values to your clipboard for easy sharing or reference.
Formula and Logic
For games without a pity system, we use the binomial probability formula:
- Probability of at least 1 drop: 1 - (1 - p)^n, where p is the base drop rate as a decimal, n is total attempts.
- Probability of exactly k drops: C(n, k) * p^k * (1 - p)^(n - k), where C(n,k) is the number of combinations of n attempts taken k at a time.
For games with a pity system, we split attempts into pre-pity and post-pity groups. Pre-pity attempts use the base drop rate, post-pity attempts use the increased pity rate. Total no-drop probability is (1 - p1)^pre + (1 - p2)^post, so at least 1 drop probability is 1 minus that value.
Expected drops are calculated as (pre-pity attempts * p1) + (post-pity attempts * p2).
Practical Notes
- Drop rates are often patch-dependent: game developers may adjust loot odds in updates, so always use the most recent in-game values.
- RNG variance means individual results will differ from calculated probabilities: you may get a drop in 1 attempt or 100+ attempts regardless of the odds.
- Pity systems vary by game: some use soft pity (gradual rate increases) rather than the fixed threshold model used here. For soft pity, use the average increased rate as your pity rate input.
- For competitive players: use this tool to estimate how many resources (gems, gold, rolls) you need to save for a target gear piece before a tournament or season.
- For game designers: balance pity thresholds and drop rates to keep player frustration low while maintaining progression pacing.
Why This Tool Is Useful
Gamers can avoid overspending resources on loot pulls by knowing the expected number of attempts needed for a target drop. Streamers can use it to explain drop odds to their audience during gacha pulls or raid loot sessions. Game designers can test loot table balance before deploying updates, ensuring gear progression feels fair.
It removes guesswork from loot planning, helping you make informed decisions about resource allocation in any game with randomized gear drops.
Frequently Asked Questions
Does this account for soft pity systems?
Some games use soft pity, where drop rates gradually increase per failed attempt rather than jumping at a fixed threshold. This tool uses a fixed threshold pity model; for soft pity, use the average increased rate as your pity rate input.
Why is my actual drop rate different from the calculated probability?
All loot drops are RNG-based, so individual results will vary. The calculated probability is the long-term expected value across many attempts, not a guarantee for a single session.
Can I use this for tabletop RPG loot rolls?
Yes, adjust the drop rate to match your table's loot table odds for a specific gear tier, and set attempts to the number of rolls or encounters. Disable pity unless your table uses a house rule for increased drop chances after failed rolls.
Additional Guidance
- Always verify drop rates in the game's official patch notes or loot table documentation before inputting values.
- If a game has multiple pity systems (e.g., separate pity for weapons and armor), run separate calculations for each gear type.
- For tabletop games, adjust the probability type to "Exactly 1 drop" if you want to calculate the odds of getting a specific magic item in a single loot roll.
- Save your calculation results to track how your actual drop luck compares to the expected probability over time.