- Enter reward values. Add the in-game value assigned to the common, rare, and legendary outcomes.
- Enter each drop chance. Use percentages from 0 to 100. The three probabilities should add to 100%.
- Set the number of drops. Enter the number of independent reward events you want to model.
- Review expected value. The main result shows average value per drop, while the breakdown reports the probability total and expected aggregate value.
- Test alternative tables. Change values or probabilities to compare balancing options.
Loot Drop Expected Drop Value Estimator
The Loot Drop Expected Drop Value Estimator calculates the weighted average value produced by one loot drop reward outcome by weighting each reward tier by its probability. It is useful when balancing loot tables, comparing event rewards, or estimating the average value a player receives across repeated drops.
The headline result is the expected value per drop. The breakdown also shows the probability total and the projected value across the selected number of drops, which helps reveal when a table is too generous, too sparse, or simply inconsistent with its intended reward budget.
Inputs
credits
%
credits
%
credits
%
drops
Result
—
Expected value per drop
Probability total—
Expected total value—
Expected value per drop = (Common value × Common probability) + (Rare value × Rare probability) + (Legendary value × Legendary probability)
Expected total value = Expected value per drop × Number of drops
Probabilities are converted from percentages to decimals before multiplication. The model assumes each drop is independent and that the listed tiers are mutually exclusive outcomes. If the probability total is not 100%, the calculator flags the table instead of normalizing it silently.
What the result means
Use the headline result as a planning estimate based on the inputs and assumptions shown above.
Change one input at a time when comparing scenarios so you can see which assumption is driving the result.
Given: common = 1 credit at 70%, rare = 8 credits at 25%, legendary = 40 credits at 5%, across 20 drops.
Calculation: (1 × 0.70) + (8 × 0.25) + (40 × 0.05) = 0.70 + 2.00 + 2.00 = 4.70 credits per drop. Across 20 drops: 4.70 × 20 = 94 credits.
Result: Expected value is 4.70 credits per drop and 94 credits across 20 drops.
This is a long-run average, not a guarantee for any individual player or short session.
What does expected drop value tell me?
It estimates the long-run average value produced by one drop under the entered probabilities. Individual drops can be worth much more or less.
Do the drop chances need to total 100%?
Yes for this three-tier model. If the probabilities do not total 100%, the table is incomplete or overlapping and the calculator asks you to correct it.
Can I use currency instead of credits?
Yes. Treat every reward value as the same unit, such as coins, points, dollars, or a normalized internal value.
Does this predict how many rare items I will actually receive?
No. It calculates expected value, not a guaranteed count or exact sequence of outcomes.
How is this different from a rarity or drop-rate calculator?
A drop-rate calculator focuses on probability. This estimator combines probability with reward value so you can compare the economic weight of the whole loot table.