What's the maximum height mobs can fall from without dying?

Solution 1:

Fall damage is calculated by the following formula:

Fall Damage = number of blocks - 3

1 damage is half a heart. (As is 1 health)

Using this formula and a list of Mob Healths, you can figure out the maximum height from which each mob can fall while staying alive. Simply subtract 1 from a mob's health and add 3!

For example, a Skeleton has 10 hearts (20 health). This means it can take 19 damage without dying. Using the fall damage formula, we can see that the maximum height a Skeleton can fall from without dying is 22.

An Enderman, on the other hand, has 20 hearts (40 health). That means an Enderman can survive a 42 block fall!

Solution 2:

The maximum height, as I remember it, is 22 blocks for a skeleton. This should leave them with 1/2 a heart left, so that they can be killed by a single punch.