In the last spoiler I picked on Superman Prime a bit to show you the truth of his powers. Now it's time for Goku. This will take the approach to things that Western Comic debaters do, EG if you can find
a Hulk Comic to back a point about his strength it counts. Author & arc do not matter.
So for this we'll look at the franchise's main continuity with the some allowance of what-if arcs, like how Death Battle used All-Star Superman's statement of strength. And in case you're wondering how the new Dragonball Super fits in, according to Super it's self it takes place between issue 519 & 520, or between Buu's defeat and the 27th world tournament. Pan serves as a pretty good marker of events, being a fetus in BoG, 1yr old in Res F, and 5 at the end of DBZ/Manga. Toriyama has also officially stated before Super that he'd rather go back in time from GT's ending and just say, "it wasn’t in the original work, but this sort of story happened" (
link)
SSj4As depicted, Vegeta is about eight time more powerful than child Goku. You can draw this from SSj3 (x400) Goku vs SSj1 (x50) Baby Vegeta. The then-still-used SSj2 transformation Vegeta is confirmed to be capable of makes him eight hundred times stronger than child Goku. Baby Vegeta then absorbs the powers of the other Super Saiyens in the series and enters a new transformation, it should be more powerful than SSj2 but for simplicity sake's let's call it that. Then Baby Vegeta ends up absorbing ALL the truffle power from everyone on Earth to enter a stat the GT authors had admitting in Perfect Files to be designed after SSj3. And then Baby Vegeta enters the Oozaru state which curiously enough keeps the hair trait of his Super Baby 2 form.
Now like a Druid's Wild Shape or a Wizard's Shapechange, the Oozaru transformation is a true metamorphosis. In the earlier Z arcs Gohan transforms into an ape that exactly looks like Vegeta's transformation even through there is a twenty to thirty year gap between the two. In GT the main hair style changes to spikes but child Goku & venerable Vegeta's ape forms are also identical, only Baby's SSj3-looking Oozaru has any unique characteristics. Now there is poorly made fan theory that Goku's SSj4 form is so powerful it breaks the black star wish, but why would the organ balls be able to grant true immorality and the black balls be limited to a superficial transformation that doesn't actually affect the user's age (except the end of GT proves it does) and why would the x10 Oozaru break the wish but not x50 SSj1? So there is no "adult body" to factor for Goku.
So let's look at the facts, it's stated in GT that you need to turn into a golden ape (super saiyen + oozaru) and take control of it to become an SSj4. The Danzenshuus confirm SSj3 is x400 & Ssj4 is "upmost limit". And
Akira Toriyama would later confirm that SSj2/Ssj3 are variants of SSj and SSj1 can surpass both. Taking SSj4 as the fusion of SSj & Oozaru and produces the maximum combination, SSj4 can canonically be said to be at least an x4,000 modifier, through as depicted against Baby it's likely a couple thousand more than that.
SSG & SSGSSSo this one is an interesting conundrum.
In Battle of the Gods SSG Goku clocks in at 60% of Beerus power and the transformation runs out forcing Goku to continue fighting on with out it, first in his base form but he quickly takes things up to the SSj1 level and he is able to continue fighting on par with Beerus's self imposed limit. We can reverse order this some, SSj1 with god ki is stronger than SSj3 Goku, just by accessioning godly ki Goku shows a better than x8 improvement over the course of events in the film.
Now Super throws an overpowered twist into this. Beerus says to Vegeta that no one has made him use more than 1% of his power meaning SSj3 Goku is weaker than that. And in turn, Goku's SSG form lasts the entire fight and forces Beerus to use 100% of his power. So according to Super, SSG is at least one hundred times more powerful than SSj3, or up to x40,000.
Goku & Vegeta are also confirmed by Whis to be able to beat Beerus, it's also noted that both the Saiyens refused to turn into a Super Saiyen during their training so it's not known for sure if Whis took into account their transformative powers or not. Behind the scenes, Toriyama confirms that in Res F Golden Frieza could not beat Beerus so likely Whis does possess a high degree of insight.
That also gives up a cap of SSGSS is slightly below Friza who is below Beerus or SSGSS isn't as powerful as Super's usage of SSG. I know it sounds a little silly, but I didn't write this plus SSGSS's dumb title aside it really is just a godly ki using Goku turning SSj, the actual SSG transformation requires a ritual not even the Gods or Shenron can apparently bypass. No ritual, no SSG, blue hair Goku isn't
the Super Saiyen God but
a Super Saiyen with godly powers after a god-transformation passed (sic 'beyond god' as in temporally, not power wise).
tl;dr: Godly ki access is like an x8 power increase and SSG is like x40,000, SSGSS isn't really SSG but kind of close to it.
There is some backwards compatibility plugged into Bog/ResF & Super compared to GT.
Like really no one really threatens Goku in GT in terms of power with the exceptions of Vegeta, Super 17 after adsorbing Goku's energy, and the Shadow Dragons. The challenges presented in the series are mostly technique based or just plain played for laughs. This construction allows Toei to empower Goku to whatever they want without actually causing any problems in GT.
And the coolest part is SSG recycling GT's transformation. Against Syn, or "Omega", Goku receives a power share from Gohan, Goten, Trunks, and Pan. Shortly afterwards he fuses with a fourth energy source completing the five energy share needed to perform the SSG ritual. And who do they become? A red haired SSG Gogeta. And just like SSG, the resulting transformation was very short lived, like BoG's SSG short, far shorter than the fusion ritual was supposed to last. Fascinating isn't it?
Kaio KenIn the anime Goku proves that he can combine the powers of the Kaio Ken with his Super Saiyen transformation. Using his fight with Lord Slug as an example, Goku's Kaio Ken capabilities allow him to temporarily increase his power by a hundred fold.
Dragon FistIn the Super 17 arc SSj4 Goku dumps his ki into the android who absorbs it all. Eventually Goku is forced to revert to his base form from exhaustion. Android 18 shows up and begins a barrage of ki and Goku surprises that Super 17 isn't absorbing her blasts and he must be defending him self from the attack allowing him to launch a counter offensive. However, the animation recycles the same absorbing scene during the same barrage so Super 17
is absorbing 18's attack and Goku's analysis is wrong or the animation is wrong.
If taken as Super 17 is blocking, it means base form child Goku super-punches a robot with about 4,000 times his own ki who is actually freaking blocking any ki attack coming his way. Under this interpretation Dragon Fist's attack power is colossally terrifying. Can you imagine anyone else with this technique? Frieza, back in the Namak arc would kill the Northern Surpreme Kai, Chi-Chi would have bested Vegeta, Krillian would have killed Cooler, and Fat Buu would have murdered Vegetto, and so on.
Alternatively, if taken as Super 17 is absorbing ki that'd mean Dragon Fist is not a ki based attack that is even capable of being absorbed. This considerably weakens the attack power of the Dragon Fist to be more like any other ki-piercing attack like Krillian's disks. But it flips it to another energy source, likely supernatural given it's ability to turn Goku into a dragon. Of course, trying to say that in a Goku vs Superman debate is impossible. Superman is as weak as a normal human against magic any kind of supernatural ability Goku might possess would allow him to instantly win with no contest.
So Dragon Fist must simply be that freaking powerful right?