The drop chance calculator helps you understand how likely you are to receive an item after several attempts.
Why is it so helpful?
Many games use random drops to determine whether an enemy or boss gives you a particular item, but when an item has a low drop chance, it can be difficult to gauge how hard it is to get.
Our tool shows the chance of getting an item not only from a single attempt, but also the probability of receiving it at least once after multiple attempts.
💡 Are you playing Minecraft? If so, our Minecraft stack calculator or Minecraft circle generator may be interesting for you to explore.
How to use the drop chance calculator
Follow the instructions below to use a drop chance calculator:
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Enter the item’s drop chance using either percentages or the “1 in x” format. You can optionally change the units of the first field to enter a decimal probability from 0 to 1.
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Determine the number of attempts you want to make.
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The drop chance calculator will estimate how likely you are to get at least one of the desired items.
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The calculator can also work in the opposite direction. If you want to reach a certain target probability, the calculator will estimate how many attempts you need.
⚠️ Keep in mind that independent random drops do not guarantee an item after a specific number of attempts. A 1% drop chance means that each attempt has a 1% chance of producing the item, regardless of previous results.
Drop chance formula
For a single attempt, the drop chance is usually expressed as a percentage or a decimal fraction. For example, a 1% drop chance can be written as 0.01. Sometimes, you can also see it as 1 in 100, meaning that, on average, you are successful once per 100 attempts.
To calculate the chance of getting an item at least once over multiple independent attempts, use the following drop chance formula:
where:
- — Drop probability for one attempt; and
- — Number of attempts.
For example, with a 1% drop chance over 100 attempts:
This means there is approximately a 63.4% chance of receiving the item at least once after 100 independent attempts. It does not mean that the item is guaranteed after 100 attempts, though.
You can explore the topic of independent events in our probability calculator for 3 events.
OSRS drop chance calculator — example
Old School RuneScape (OSRS) uses drop tables with different probabilities for many monsters and bosses. A drop chance is often presented as a fraction, such as 3/100, meaning an item has a 3 in 100 chance of being selected on an eligible drop roll.
For example, if an item has a 3/100 drop chance, the probability on each eligible roll is 3%. After 10 independent rolls, the chance of getting the item at least once is:
After 100 rolls, the probability increases to approximately 95.2%. You can freely use our tool as an OSRS drop chance calculator for your needs.
A 1/100 drop does not mean that you will receive the item exactly once every 100 kills. Random results in OSRS can produce several drops close together or no drops over many attempts.
FAQs
What are the chances of a Terraria boss dropping nothing?
The chances of a Terraria boss dropping absolutely nothing are 0% under normal gameplay conditions, as every boss has guaranteed core items.
Some items may have conditional drops, but the chances of obtaining them vary between the types of items and bosses.
What is the chance of a Wither Skull dropping?
In Minecraft, a Wither Skeleton has a 2.5% chance to drop a Wither Skeleton Skull when killed by a player or a tamed wolf. Looting enchantment can increase the maximum drop chance to 5.5% with Looting III.
What is the Hellfire Torch drop chance?
The commonly reported drop chance of the Hellfire Torch in Blox Fruits is around 1%-2% per Cursed Captain defeat, although the exact rate is not officially published.
This means you may need many attempts before obtaining the Torch. For example, to have a 50% chance of getting at least one Hellfire Torch, you need to defeat Cursed Captain about 69 times at 1%, or around 34 times at 2%. You can use a drop chance calculator to estimate other chances.
What is the chance of a drowned dropping a trident?
In Minecraft Java Edition, the overall chance of getting a trident is about 0.53% (1 in 188). To get this value, multiply the chance of a Drowned holding a trident (6.25%) by the trident drop chance (8.5%). With the Looting III enchantment, the overall chance increases to about 0.72% (1 in 139).
In Minecraft Bedrock Edition, the corresponding figures are 15% and 25%, resulting in an overall chance of 3.75% (1 in 27) or 5.55% with Looting III (1 in 18).