I just want to make a few things flat out before I start the story.

First, note a few extremely important things. I feel that the Power Levels of people are many times greater than people actually say. Its truth that even Raditz could have blown up the Earth if he had come in the night, yet that would take a Power Level of 10 20 (ten with twenty zeroes). So get used to seeing the Power Levels at the bottom of each episode being in this format.
Secondly, I believe the Super Saiyan transformations multiply the Saiyan's power incredibly: For instance, Super Saiyan 1 multiplied Goku's power by 10 50 (ten with fifty zeroes), and Super Saiyan Second Grade will multiply it by 10 200 extra onto the Power Level. Just to simplify it, I'll put each SSJ (Super Saiya-Jin) transformations and what they will multiply the user's power by.
Secondly, I believe the Super Saiyan transformations multiply the Saiyan's power incredibly: For instance, Super Saiyan 1 multiplied Goku's power by 10 50 (ten with fifty zeroes), and Super Saiyan Second Grade will multiply it by 10 200 extra onto the Power Level. Just to simplify it, I'll put each SSJ (Super Saiya-Jin) transformations and what they will multiply the user's power by.

SSJ: 10 10,000,000,000
SSJ 1.25: 10 100,000,000,000
SSJ 1.5: 10 1,000,000,000,000
SSJ 1.75: 10 10,000,000,000,000
SSJ 2: 10 100,000,000,000,000
SSJ 2.5: 10 1,000,000,000,000,000
SSJ 3: 10 10 20
SSJ 4: 10 10 200

Oozaru: 10 1000

Super Saiyan Oozaru: 10 10 40
Golden Oozaru: 10 10 40
Super Saiyan Golden Oozaru: 10 10 80
Controlled Super Saiyan Golden Oozaru: 10 10 100

Kaio-Ken: 10
Kaio-Ken x2: 20

Kaio-Ken x1,000,000: 10,000,000

Understand that I am sticking with the description that Pivitor made of Super Saiyan 4. Its is a EVOLVED Saiyan, therefore making it stronger than Mystic or any unevolved Saiyan.
However, I'm adding that there IS such a thing as a Golden Oozaru and instead of being able to transform from Super Saiyan Oozaru to SSJ 4, it must be Controlled Super Saiyan Golden Oozaru to SSJ 4.

-------------------------

Anyway, this is also in a timeline much ahead in power of that of the Z Fighter's current timeline. The power increases come in Forms, although the weakest of the weak in the universe will use Perfect Saiya-Jin as their maximum power increase.
We will go back a step of the power to reach Super Saiya-Jin 5. Its power equals that of Black Star Shenron, and in fact the two forces collided previously resulting in the eventual winning of the Super Saiya-Jin 5. Super Saiya-Jin 5 Second Grade once again multiplies the power increase from Super Saiya-Jin 5 by Infinite, meaning that from base form to SSJ 5.25 makes you Infinite x Infinite times stronger.

Now that you understand these steps, you should be able to guess that the Super Saiya-Jin levels go on forever. But, when you're high enough, if you're lucky you will go straight to Perfect Super Saiya-Jin. Otherwise, you will keep going.
Anyway, Super Saiyan Infinite means that you have a power that can be explained like this:

Do Infinite x Infinite x Infinite, and keep adding "x Infinite"'s for Infinite times. Then, multiply that by four.

But, going to PSJ will mean that this will be the formula for you:

Do Infinite x Infinite x Infinite, and keep adding "x Infinite"'s for Infinite times. Then, multiply that by Infinite to reach Infinite µ 1.

Now, the first person ever to become a Perfect Super Saiya-Jin was Goku himself, followed closely by Vegeta. But soon enough more and more people got Perfect Saiya-Jin until only the weakest of the weak had not got it. Many people reached into Perfect Saiyan 6, or Perfect Saiyan 7.

PSJ 2: Infinite µ 10 2
PSJ 3: Infinite µ 10 3
PSJ 4: Infinite µ 10 4

So on. The strongest of the strong normal people breached into an omega PSJ 21, but the Z Fighters went even further. The weakest of the Z Fighters of all, Pan, was a PSJ 35. And when the Z Fighters fused, they had the power of a PSJ 50 in BASE FORM, and could power up to an unbelievable PSJ 200. The fusion, known as Z Goku, had a tussle with the Legendary Elite, Matt, who defeated it by going to FORM 2. In Form 2, he was 10 Infinite times stronger than FPPSJ 200 Z Goku using a 10 -Infinite th of his (Matt's) power in BASE FORM.

FP PSJ 250 Z Goku: Infinite µ 10 260

Form 2 Matt -10 -Infinite of his power, Base Form: (Infinite µ 10 260) x Infinite

The power-up from Form 1 to Form 2 was immense, so imagine ten times that power. Ten times the POWER-UP from Form 1 to Form 2 would be the power-up from Form 2 and Form 3. So, for instance, say that Form 2 equalled 1, look at this chart.

Form 2: 1
Form 3: 10
Form 4: 100
Form 5: 10 3
Form 4: 10 4
Form 5: 10 5

So on.

Now, let's move on in the power timeline one saga, to begin the new saga. Matt is very weak now, and its his son Hiro who is the strong power. Hiro has an unbelievable Form Infinite that he's concealed from his parents of fear of their shock. But when a child from the "Power School" confronts his father's planet, Matt is forced to go to it. In it, he simply has to say: "Maximum Saiyan Level!" to go to his highest Saiyan Level. To go to full power, he has to add on "Full Power!" at the end.
By the end of this new Saga, the line has been simple: He defeats one enemy with a new form, and then a new one comes that effortlessly beats him. At the end, he faces of a Ultra Power William Fitter Powerlinx Complete and wins with Form Infinite x Infinite, also known as LEVEL 1.
By the end of the next saga, Hiro achieves Level 3 and has found 4 four friends: Jerome, a powerful Saiyan trainer who has been searching the universe for the ultimate power, Hiro, to fight; Kate, Mia's older sister and a brilliant fighter with enough skill to take down Hiro the first time they fought; And Mia, a slightly babyish little girl who is usually more trouble than power. By the beginning of Saga 3, he knows his friends well and has achieved Level 6 at the end. Saga 4, the Evil Beasts Saga, makes him Level 10, and by the next one, the Minland War Saga, he ends up Level 15 at the end. By the end of Saga 6, the World Tournament 1 Saga, he is Level 21. Next comes the Bibidi Saga: By the end, he is Level 30. Now, look at it in this order.

Saga 8, Babidi Saga: Level 40 by end
Saga 9, Bubidi Saga: Level 60 by end
Saga 10, Bobidi Saga: Level 90 by end
Saga 11, Babidi's Together Saga: Level 200 by end

Saga 25, Ultimate Saga: Level 10 25 by end