What inheritance rule does this use?

It uses the common Destiny-Knot model where 5 of the 6 IV slots are inherited from a randomly chosen parent for each slot, and the remaining slot is rolled fresh from 0 to 31. Each target perfect IV is assumed to be held by exactly one parent.

How is the per-egg chance calculated?

The tool conditions on which single slot is re-rolled, uniformly across the six stats. Inherited target stats each need the right parent picked at 1/2, and a target stat that lands in the re-rolled slot must hit 31 at 1/32, all averaged over the six cases.

Why do the odds drop so fast for more perfect IVs?

Each additional perfect IV multiplies in another 1/2 factor for picking the correct parent. Four perfect IVs are realistic to farm, five is a long grind, and six is rare enough that breeders usually use it as a trophy goal.

How many eggs will I need?

Expected eggs is one divided by the per-egg chance. If the chance is 1.3%, you should expect roughly 77 eggs on average, though variance is high so any single attempt may take far more or fewer.

Does this cover nature or hidden ability?

No. This calculator focuses on IV inheritance probability. Nature passing with an Everstone and hidden ability inheritance are separate near-certain or fixed-rate mechanics you can layer on top of these odds.

Apex Legends Breeding & IV Calculator

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Breeding for perfect IVs is a numbers game, and the difference between four and five perfect stats is a huge jump in grind. This calculator uses the standard Destiny-Knot inheritance rule to give you the real per-egg odds and the expected number of eggs to hit your target.

How it works

With a Destiny Knot, 5 of the 6 IV slots are inherited from a randomly chosen parent per slot, and one slot is rolled fresh. Assuming each target perfect IV is held by exactly one parent, the per-egg success probability is found by averaging over which slot is the re-rolled one:

for each of 6 possible re-rolled slots:
  inherited targets each need the right parent → (1/2) each
  a target in the re-rolled slot must hit 31   → ×(1/32)
P(per egg)     = average of those 6 cases
expected eggs  = 1 / P(per egg)

Example and tips

For a 4-perfect-IV target the per-egg chance is a little over one percent, so expect dozens of eggs. To improve your odds, breed parents that together cover as many of your target stats as possible at 31 — every perfect IV you supply removes a factor of one half from the difficulty. Use an Everstone to lock nature without affecting these IV odds, and hatch in bulk to push through the variance.