So I am assuming you are taking about when you start at 0, caught in normal pokeball, and when you are Playing USUM, since friendhsp mechanics differ game to game. Also bulbapedia says that every 128 steps it will sometimes increase happiness, but I wont be counting that since otherwise this question will be unanswerable. So here we go:

## USUM/SM

Without Soothe Bell: (199*2+55*1)*128=57984

With Soothe Bell: 57984/(3/2)=38656

## XY/ORAS

Same as gen 7

## BW/B2W2

It has a 50% chance each time to raise friendship, and a 50% chance not to, but you could either get really lucky or really unlucky so I wont include that.

Other than that it is same as USUM.

## DP/Pt/HGSS

It has a 50% chance each time to raise friendship, and a 50% chance not to, but you could either get really lucky or really unlucky so I wont include that.

Without Soothe Bell: 255*128 = 32640

With Soothe Bell: 32640/(3/2) = 21760

## RSE/FRLG

It has a 50% chance each time to raise friendship, and a 50% chance not to, but you could either get really lucky or really unlucky so I wont include that. Also in this gen the max you can get by walking is 199 happiness. The other 56 friendship have to be earned in some other way.

Without Soothe Bell: 199*128 = 25472*

With Soothe Bell: 199128 = 16981 or 16982. It ended it .3 repeating.

## GSC

There is no soothe bell in this gen.

512 * 255 = 130560

This is of course not exact, since of all the probability involved but, like I said, this answer would be unanswerable while including the probability.

Source

Soothe Bell source was from sumwun