Spin a Catboy Pack Odds Calculator
Official rates turned into expected opens. No slider that lies.
This calculator is a table, not a promise. Mugpugs published Secret rates in the Roblox description. We multiply them. We do not add a luck slider that pretends LUCK is +400%.
Use it with how to get Secrets and pack ranks. Fill the Base first; math does not help an empty plot. See getting started.
Official rates we are using
| Pack | Secret rate | Super Secret (about 1/10 of Secret) |
|---|---|---|
| Eclipse | 1/100 | ~1/1,000 |
| Costs 50B | 1/150 | ~1/1,500 |
| All other packs | 1/100,000 | ~1/1,000,000 |
The thumbnail 1/397,897,213 is art. It is not in this table.
Expected Secrets (average, not a guarantee)
| Opens | Eclipse Secrets | 50B Secrets | Other Secrets |
|---|---|---|---|
| 1 | 0.01 | 0.0067 | 0.00001 |
| 10 | 0.10 | 0.067 | 0.0001 |
| 50 | 0.50 | 0.33 | 0.0005 |
| 100 | 1.00 | 0.67 | 0.001 |
| 150 | 1.50 | 1.00 | 0.0015 |
| 500 | 5.00 | 3.33 | 0.005 |
| 1,000 | 10.00 | 6.67 | 0.01 |
Read it as: 100 Eclipse opens average one Secret. You can still go 0/100. 1,000 cheap opens average 0.01 Secrets. That is why cheap crates are filler.
Chance to see at least one Secret
Approximate “did I see one” odds, using 1 − (1 − p)^n:
| Opens | Eclipse | 50B pack | Other |
|---|---|---|---|
| 10 | ~10% | ~6% | ~0.01% |
| 50 | ~39% | ~28% | ~0.05% |
| 100 | ~63% | ~49% | ~0.10% |
| 200 | ~86% | ~74% | ~0.20% |
| 500 | ~99% | ~96% | ~0.50% |
A 63% chance after 100 Eclipse opens is not a coupon. Bring a bankroll for 200 if you want to sleep.
Super Secret column (Eclipse only, the only hunt that makes sense)
| Eclipse opens | Expected Super Secrets | Chance of at least one (~1/1000) |
|---|---|---|
| 100 | 0.10 | ~10% |
| 500 | 0.50 | ~39% |
| 1,000 | 1.00 | ~63% |
Do not run this table on cheap packs. A million opens is not a session.
How to use this in a real night
- Count how many Eclipse or 50B packs you can afford without selling a placed Secret.
- Find the row. If expected Secrets are under 0.5, you are buying a ticket, which is fine if you know it.
- Open that number. Stop. Place whatever dropped. See upgrade the Base.
- Do not “make it back” on 1/100,000 crates.
LUCK (119 Robux) is not modeled here because Mugpugs did not publish a percentage. 2X CASH is not modeled because it changes income, not p. Auto Skip changes time, not p.
Codes such as ILOVECATS add some number of packs or cash. Add those opens to the row after you redeem, not before.
This page will gain a new row if the description changes. Until then, Eclipse is the only crate whose math looks like a hunt.
Frequently Asked Questions
Quick answers to the most common questions.
How many Eclipse packs for one Secret?
On average, 100. You can need more. 100 opens is about a 63% chance to see at least one.
How many cheap packs for one Secret?
On average, 100,000. Do not hunt that way.
Does this include LUCK?
No. The pass has no published percent, so we do not fake one.
Is Super Secret 1/10 of Secret?
That is the official wording. Eclipse Super Secret is modeled at about 1/1,000.
Where are the rates from?
The live Roblox description for Spin a Catboy by Mugpugs.