Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Chance of at least one
41.82%
Pulls for your confidence level
383
Expected pulls per hit
167
Cost of your planned pulls
$180.00
Worst-case cost to hard pity
$180.00
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter drop rate per pull (%).
- 2Enter pulls you'll make.
- 3Enter target confidence (%).
- 4Enter cost per pull ($).
- 5Enter hard pity at pull #.
- 6Read your chance of at least one on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Independent pulls compound differently than intuition suggests. Compute the chance of at least one success across a number of pulls, the pulls needed for a target confidence, and the currency cost.
Worked example
Using the values the calculator loads with:
Inputs
- Drop rate per pull: 0.6 %
- Pulls you'll make: 90
- Target confidence: 90 %
- Cost per pull: 2 $
- Hard pity at pull #: 90
Results
- Chance of at least one: 41.82%
- Pulls for your confidence level: 383
- Expected pulls per hit: 167
- Cost of your planned pulls: $180.00
- Worst-case cost to hard pity: $180.00
What each field means
Inputs
- Drop rate per pull (%)
- The drop rate per pull used in the calculation, measured in %. Starts at 0.6 % so you have a working example on load. Accepted range: 0.01–100 %.
- Pulls you'll make
- The pulls you'll make used in the calculation. Starts at 90 so you have a working example on load.
- Target confidence (%)
- The target confidence used in the calculation, measured in %. Starts at 90 % so you have a working example on load. Accepted range: 1–99.9 %.
- Cost per pull ($)
- The cost per pull used in the calculation, measured in $. Starts at 2 $ so you have a working example on load.
- Hard pity at pull #
- The hard pity at pull # used in the calculation. Starts at 90 so you have a working example on load.
Results
- Chance of at least one
- Returned as a percentage and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Pulls for your confidence level
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Expected pulls per hit
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cost of your planned pulls
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Worst-case cost to hard pity
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Does a 1% rate mean 100 pulls guarantees it?
No. At 1%, 100 pulls gives roughly a 63% chance. Reaching 99% confidence takes about 459 pulls.
Does soft pity change this?
Yes — rates that ramp near the pity threshold beat the flat model. Treat this as the floor, not the exact curve.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Gacha Pull Probability Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/gacha-pull-probability
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/gacha-pull-probability" target="_blank" rel="noopener">Gacha Pull Probability Calculator — RevenueLab</a> (2026).</p>
Source: [Gacha Pull Probability Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/gacha-pull-probability) (2026).