Gacha Pull Probability Calculator
Works out your chance over a run of gacha pulls, at a flat rate.
Chance of getting the copies wanted
— %
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
Average copies from these pulls —
Cost of these pulls —
Pulls for a 50% chance of one copy —
Pulls for a 90% chance of one copy —
Reading this —
The formula
one copy: 1 − (1 − rate)^pulls several copies: 1 − the binomial chance of fewer than that number
This uses the published base rate for every pull.
What to watch out for
Banner rules such as a guaranteed pull or a 50/50 on the featured item raise or lower these figures. Check the game’s published rates.
Frequently Asked Questions
What is the chance of a 0.6% item in 90 pulls?
41.82% at a flat rate, with no pity.
And two copies?
10.21%.