Pet Sim 99 hatch odds calculator
Huge rates run from 1-in-100 to 1-in-millions. This page shows what those rates actually translate to over N hatches.
The math behind Huge hatches
A Huge in Pet Simulator 99 is a giant variant of a base pet, and the per-hatch rate is usually somewhere between 0.5% and 0.001%. Each hatch is independent, so the formula is the same one used in every drop-rate calculator: 1 − (1 − p)N.
What makes PS99 hatching feel different is the scale. At a 1-in-100,000 Huge rate, the 50% median is around 70,000 hatches and the 90% median is 230,000 hatches. Players running 24-hour auto-hatch sessions still find Huges at those rates — but it takes patience, which is the whole point of the genre.
Lucky boosts (from gamepasses, codes, or rebirth perks) multiply your effective rate. A 2× luck boost at 1-in-100,000 becomes 1-in-50,000 — type the boosted percentage in if you have one running.
When to use it
- Deciding whether to keep grinding an egg or switch to a different farm.
- Comparing newest event eggs against last season's rates.
- Sanity-checking a friend's "I hatched 50k and got nothing" story (probably normal).
Worked example
You're chasing a Huge at a 1-in-50,000 rate, with a 1.5× luck boost (so 1-in-33,333, which is about 0.003%). Enter 0.003 and 30,000 hatches. The calculator reports a chance of about 59% — better than even odds, but a 41% chance of leaving empty-handed. The 50% median is around 23,000 and the 90% median is around 77,000.
FAQ
Are rates the same across servers?
Yes — drop tables are server-side and global to the game.
Does the calculator handle Titanics?
Same math, different rates. Type the Titanic's per-hatch rate (usually a tenth of the Huge rate or smaller) directly.
What about Shiny / Rainbow / Golden modifiers?
Those are separate rolls on top of the hatch. To estimate "Huge AND Shiny," multiply the Huge rate by the Shiny rate and use that as p.