Calcvers
Drop Rate Calculator
Odds & Drops
Generated
September 24, 2026
Chance after 20 runs
64.2%
at a 5% drop rate
Your inputs
- Drop rate
- 5 %
- Runs
- 20 runs
- Target chance
- 90 %
Breakdown
- Expected runs
- 20
- Runs for 90%
- 45
- Chance at +10 runs
- 78.5%
Cumulative chance curve
| Item | Value |
|---|---|
| 20 | 64% |
| 25 | 72% |
| 30 | 79% |
| 35 | 83% |
| 40 | 87% |
What this means
Each run is independent, so the chance of having gotten the item after n runs is 1 − (1 − p)ⁿ, where p is the per-run rate. It never reaches 100%. The expected runs (1 ÷ p) is the average, but averages mislead here — a 5% drop takes about 20 runs on average, yet a third of players still won't have it after 20, and about 2% are still empty-handed after 90. This calculator shows both the chance and the runs to a comfortable target.
Recommendations
- Use the 'expected runs' as your planning baseline, but expect streaks on either side.
- Pick a run target you're comfortable 'wasting' before you start — loss aversion strikes hard here.
- For gacha-style odds, compare accumulated spend against the run counts to keep budgets sane.
Watch out
- Each run independent means past runs never guarantee future ones — the drop rate is reset every attempt.
- A low drop rate can take far more runs than the average suggests; tail risk is real.