>##Generations II to V##

Hidden Power inflicts damage using a *type and base power determined by the user's IVs.*

Hidden Power *can receive same-type attack bonus.* For instance, a Bug-type Pokémon will receive same-type attack bonus when using a Bug-type Hidden Power. Although Hidden Power is Normal-type in the game's data, a Normal-type Hidden Power is not obtainable.

Hidden Power is unaffected by Normalize.

Calculations:

### Generation 2

Type: This was decided in this way

**HP Type = a mod 4 + b mod 4**,

where:

- 'a' is the Attack IV,

- 'b' is the Defence IV

-" 'mod' is modulo. Modulo is such that "b mod a" is the remainder of b/a ". Credits to PhysicsForums

Power:

HP Power = (5* {v + 2w +4x + 8y} + z) / 2

where:

v depends on the Special IV.

w depends on the Speed IV.

x depends on the Defense IV.

y depends on the Attack IV.

### Generation 3-4

[5 and 6 also]

Type:

HP Type = [(a + 2b + 4c + 8d + 16e + 32f) * 15]/63

where:

a depends on the HP IV.

b and c depend on the Attack and Defense IV's respectively.

d depends on the Speed IV.

e and f depend on the Special Attack and Special Defense IV's respectively.

Power (Before Gen 6)

HP Power =[ {(u + 2v + 4w + 8x + 16y + 32z) * 40}/ 63 ] + 30,

where:

u depends on the HP stat.

v and w depend on the Attack and Defense stats respectively.

x depends on the Speed stat.

y and z depend on the Special Attack and Special Defense stats respectively.

There you have it! Very confusing, I know, but just maths in the end. A whole lot of it.