Steal a Brainrot Lucky Block Odds Calculator

Estimate the chance of at least one target across several openings.

Enter 0–100 without a percent sign, using up to 8 decimal places. Editing a preset switches to Custom.

A whole number from 0 to 1,000,000,000. This is a probability model, not a purchase recommendation.

How the estimate works

For a fixed per-opening chance p and n independent openings, the chance of at least one target is:

1 − (1 − p)n

Example: a 3% chance over 10 openings gives about 26.2576% for at least one target and 73.7424% for none. Reaching at least 95% takes 99 openings under the same assumptions. Example fills the form; press Calculate to try it.

Does 95% mean I will get the drop?

No. The model estimates a 95% chance of at least one target over that many openings; the remaining failure chance is nonzero. Rounded near-100% results do not establish certainty.

Do failed openings improve the next chance?

The model keeps p fixed for every independent opening. It does not assert or model a pity system. Check for special rules in game that could change the chance.

The formula is the complement of zero successes in the binomial model described by NIST. That mathematical model does not verify the game's randomisation rules.

Sources and limits

25 normal-pool rates across four blocks, checked November 5, 2026. Dates below are community page edits, not game-observation times. These references do not confirm current availability, boosts or special Sammy-base pools.

Are these live in-game rates?

No. These are dated community references, not a current in-game test. If you have a rate you observed in game, use Custom to enter it. A rate does not establish that a block is obtainable now.

Can I add luck or mutation boosts?

No verified probability conversion is available here for luck, passes or mutations. Mutation income multipliers are a different task and must not multiply drop chances. Known exist counts describe reported copies, not your chance of a drop.

Reference data adapted from the Steal a Brainrot Wiki community, with formatting and field selection changes, under CC BY-SA 3.0. Adapted reference data is available under the same license.