Drop Calculator

The Drop Calculator (introduced in ATMA 5.04) supports versions 1.07-1.11 and includes many features. This calculator will define the odds of finding any given item based on the monster or monsters selected, or will give the odds for each monster given a selected item. You can input the "players" setting and magic find, then choose the desired monster, monster type, item, or item type.

The Drop Calculator is packed full of great features:
  1. Full support for Diablo 1.07, 1.08, 1.09, 1.10 and 1.11.
  2. Correct scaling of creature mlvl and TC upgrade in Diablo 1.10+ (Nightmare and Hell).
  3. Sorting of results by name, probability or creature location.
  4. Display of probabilities as fraction, percentage or odds.
  5. Sorting of probabilities in ascending or descending order.
  6. Ability to search by monster or by item
  7. Full support for "players X" and character MF
  8. Both item and monster search allow you to customize the parameters by which you choose to search
  9. Changing either your MF or # of players requires the user to hit the "Search" button.

For the mathematically inclined, the options for calculating drops are:

  • Chance Per Drop
    Let the probability for an item to drop per unique drop path be p_i and let the frequency for each of those paths be c_i. Then, the probability per drop is simply SUM(p_i, i=1...n).

  • Chance Per Kill
    The probability of at least one item per kill is 1 - PRODUCT( (1 - p_i)^(c_i) )

  • Expected # of items per kill
    The expected # of items per kill is given by SUM(p_i * c_i, i=1...n).

    The default value (and most reliable) is the second option above since you would like to know what your odds of finding at least one of those items across all potential drops.