Drop Rate Calculator
Turn a drop rate into real odds: the chance you would have the item by now, how many attempts a 90% or 99% chance really takes, and how long that grind lasts.
Drop chance
%
1 in
Effective rate:
— about attempts.
Your grind
Kills, runs, chests or rolls.
Adds real-world time estimates to the table below.
Chance of
in
attempts
Expected drops
Still empty-handed
Average attempts
Cumulative chance over attempts
Attempts — the dashed line marks your current attempts.
Attempts needed for a given confidence
| Confidence | Attempts | Time |
|---|---|---|
There is no such thing as being "due"
Unless a game has explicit bad-luck protection, every attempt is independent: the chance on your 500th kill is exactly the same as on your first. That is why the average attempts figure is not a guarantee — roughly 37% of players still have nothing after grinding out the full 1-in-N average.
Features
- Chance of getting at least one drop — or any number of copies — in a given number of attempts
- Accepts drop rates as a percentage or as "1 in N" odds
- Expected number of drops and the odds you are still empty-handed
- Attempts needed to reach 50%, 75%, 90%, 95% and 99% confidence
- Cumulative probability chart with a marker at your current attempt count
- Optional seconds-per-attempt input to convert every milestone into real grinding time
- Exact binomial maths, so multi-copy farming (weapon parts, tokens, mounts) is handled correctly
- Quick presets for common rates like 1%, 0.5% and 1 in 4096
How to Use
- Pick whether your drop rate is written as a percentage or as 1 in N, then enter it.
- Enter how many attempts you have made (or plan to make) — kills, runs, chests or rolls.
- Set how many copies you need if you are farming more than one.
- Read the headline figure: the probability you would have the drop by now.
- Check the confidence table to see how many attempts a 90% or 99% chance really takes.
- Optionally add seconds per attempt to turn those milestones into hours of grinding.