Hatch Probability Calculator
Odds of hatching at least one rare pet from your planned hatches
e.g. you hatched 3 rares in 200 eggs → 1.5
Chance of ≥1
—
Expected successes
—
Chance of zero
—
| Hatches | Chance of ≥1 | Expected successes |
|---|
We deliberately don't ship a "known drop rate" list — the developer publishes none, and every site claiming exact rates is guessing. Use a rate you observed yourself: count your rares, divide by your total hatches, enter it above.
The math behind the hatch odds
Each hatch is an independent trial with your observed success chance p. The probability of getting zero rares in n hatches is (1 − p)n, so the chance of at least one is 1 − (1 − p)n — that's the headline number above. Expected successes are simply n × p.
Two intuitions this table fixes. First, luck doesn't warm up: 100 hatches at 1% is always ~63% for at least one, no matter how dry your last 100 were. Second, doubling hatches does not double your odds — it roughly squares the chance of failure, so going from 100 to 200 hatches at 1% only moves you from 63% to 87%, not to 126%.
To raise p instead of grinding more eggs, see the how to get rare pets guide, and use Coins per Hour to check whether more hatches or a better egg is the smarter use of your time.
Read before you calculate
More free Steal an Egg tools
Rare Egg Window Timer
Count down the 5-minute rare egg window before it despawns
Coins per Hour Calculator
Estimate your farming income from runs, success rate, and payout
Steal Risk Calculator
Compare your Speed against a target before you grab the egg
Rebirth Planner
Plan rebirths: total cost, income growth, and hours to your goal
Trade Value Calculator
Total both sides of a pet trade and see who comes out ahead