How blind box odds work
Blind box odds are often easier to understand when you turn the set size into a single-box success rate. If a series has 12 equally likely designs and you only want one of them, a single box is roughly a 1 in 12 chance, or 8.33%.
Buying more boxes improves your chance, but it does not remove the possibility of duplicates unless the seller is opening from a sealed case with known distribution rules. This calculator uses the simple independent model because that is the fairest estimate for loose boxes, online orders, and mixed inventory.
If you would be happy with more than one figure, enter the number of desired variants. For example, if you like 2 designs out of 8, the single-box success rate is 25%. That can make a practical difference when deciding whether to buy one box, a few boxes, or wait for a confirmed resale listing.
Formula
single-box rate = desired variants / total variants; P = 1 - (1 - rate)^boxes The calculator first estimates the chance that one blind box contains any item you want. It then applies the at-least-one formula across the number of boxes you plan to buy.
This works best when variants are evenly distributed. Secret figures, chase variants, weighted odds, and case guarantees can change the real probability. If a secret item has a published rate, use that known rate in the general at least one success calculator instead.
Example use cases
One target out of 12 designs
Buying 3 boxes from a 12-design series gives about a 22.97% chance of getting that one specific design, assuming equal odds and independent boxes.
Two favorites out of 8 designs
If you like 2 designs in an 8-design set, each box has a 25% chance of being useful. Three boxes gives about a 57.81% chance of at least one desired figure.
Secret item odds
Some secret items are not evenly distributed. If the secret is truly 1 out of 144 boxes, use 0.694% as the success rate in the at least one success calculator.
Responsible use
Probability can help you understand risk, but it cannot guarantee a win. If you are buying pulls, boxes, packs, or prize tickets, set a budget first and avoid spending more than you can afford. A calculator is a planning aid, not a reason to chase losses or ignore your limit.
FAQ
Does this assume every blind box has equal odds?
Yes. It assumes each variant is equally likely unless you combine desired variants into a simple rate. Weighted secrets or case rules can change the result.
Does this account for sealed case guarantees?
No. Sealed case distribution is a different problem because boxes may not be independent. This tool is best for loose boxes or ordinary online purchases.
What should I enter for a secret figure?
If the secret has a known published rate, use the at least one success calculator. If no rate is known, any result is only a rough estimate.
Can this help me compare buying boxes versus resale?
Yes. Add the price per box and compare the estimated cost with the resale price, but remember that probability still does not guarantee a hit.
Related tools
Random Booster Calculator
Calculate your chance of getting a desired variant from random booster packs or collectible toy packs.
Expected Cost
Estimate how much you may spend to reach a target probability in gacha pulls, blind boxes, or random packs.
At Least One Success
Calculate the chance of getting at least one success after multiple attempts, or find how many attempts you need.
Helpful guides
How Gacha Probability Works
Learn how gacha probability works, why repeated pulls do not add up directly, and how to read at least-one-success odds.
Blind Box Odds Explained
Understand blind box odds, equal variant assumptions, secret item limits, duplicate risk, and how to compare boxes with resale prices.