Drop rate calculator
Your chances of getting a rare item after X tries, and how many tries to be almost sure.
How it works
Chance of at least one drop = 1 − (1 − rate)^tries. Tries for probability p = ln(1 − p) / ln(1 − rate). Each try is independent: bad luck doesn't "build up".
Results are for guidance only and do not replace professional advice.
Worked example
With the default values:
- Drop rate (%)1.5
- Number of tries100
you get:
- Chance of at least 1 drop77.94 %
- Expected drops on average1.5
- Tries for a 50% chance46
- Tries for 90%153
Frequently asked questions
How does the “Drop rate calculator” tool work?
Chance of at least one drop = 1 − (1 − rate)^tries. Tries for probability p = ln(1 − p) / ln(1 − rate). Each try is independent: bad luck doesn't "build up".
What do I need to enter?
Just fill in: drop rate, number of tries. The result updates as you type.
Can you give an example?
Drop rate (%): 1.5; Number of tries: 100 → Chance of at least 1 drop: 77.94 %; Expected drops on average: 1.5.
Is this calculator free, and is my data private?
Yes. HOD Calc is completely free with no sign-up. The calculation runs in your browser: nothing you type is sent or stored.