Original calc here: https://forums.hero-academia.com/xfa-blog-entry/calc-requests-part-26.36253/
I found out that there are some mistakes and errors in that calc, he used fragmentation instead of pulverization (since it was a crater), and he used the California diameter only instead of the West Coast diameter.
Re-doing the calc:
Based on this comic, P.E.P.P.E.R. calculated that the bomb will turn the West Coast of the United States into a crater. That would be the sheer KE of the bomb, and Iron Man stopped it. To find the kinetic energy of the bomb, let's determine the diameter of the West Coast:
Using D/4 crater depth:
1,910.58 km / 4 = 479.645 km
By using the ellipsoid volume calculator in Google , the volume will be 7.33 * 10^9 km^3, or 7.33 * 10^24 cc.
Hard to tell if I am gonna use pulverization or vaporization. On the other hand there is no evidence to suggest if the crater will leave a dust, but we don't know if the West Coast-sized crater that will be formed by the bomb have no remaining dust on it, so we'll use pulverization.
Using rock pulverization: 7.33 * 10^24 cc * 214.35 joules/cc = 1.5711855 * 10^27 joules
= 1.5711855 * 10^27 joules or 375.522 petatons of TNT (Multi-Continent level)
Not a bad upgrade for Iron Man. So High 6-A for his Armor Model 45.