Premise
Frankie survives a boom.
Feat here
Heights
Frankie's actor Shuler Hensley is 1.905 m tall.
According to this, Frankie is 360 lbs or 163.293 kg.
Surface area calculator go! 2.94 m^2. We need cross-sectional area, usually 40% for normal-sized people, but Frankie is not normal sized, he's heavy and has considerable mass on him. So I'll go 50% of that. 2.94*0.5 is 1.47 m^2 affected.
Pixel-scaling
Okay. First orders of business.
The door at the top (Black) is the same height as Frankie. 1.905 m. It is 60px.
The windmill width (Red): 325px= 1.905*(325/60)= 10.31875 m diameter. Same diameter as boom. Radius is 5.159375 m.
Explosion calc thingy
Ground-based since it also happened on the ground and Frankie fell to the bottom.
W = R^3*((27136*P+8649)^(1/2)/13568-93/13568)^2, where W is the yield in tons of TNT, R is the radius in meters, and P is the shockwave pressure in bars, where we generally use 1.37895 bars or 20 psi of pressure. For this specific formula, there is no need to divide the result by 2.
However, 20 psi is for reinforced concrete and other large structures made of sturdy rock or giant earth-like stuff.
For wood, it's even worse. 6 psi or 0.413685 bars. It sent a gigantic metal cog flying but not sure how to derive psi from that, so uh...
W = 5.159375^3*((27136*0.413685+8649)^(1/2)/13568-93/13568)^2= 0.00171728076 tons of TNT or 7185102.69984 J (9-B). Fuck.
But wait, it gets even worse!
Frankie wasn't near the explosion source, the sources were a bunch of bottles set up near the windmill walls. So it's safe to assume he was a radius away from the explosion. 5.159375 meters.
Inverse-square law bullshittery time.
I (Yield tanked)= (explosion yield in tons of TNT) / (4π((Distance from explosion in meters)^2))
I= (0.00171728076) / (4π((5.159375)^2))= 0.00000513377 tons of TNT or 21479.69368 J (9-B), very baseline.
Now I multiply it with cross-sectional area.
Yield tanked by Frankie: 1.47*0.00000513377= 0.00000754664 tons of TNT or 31575.14176 J (9-B)
FUCK.
Tallies
Frankie's explosion: 0.00000754664 tons of TNT or 31,575.14176 J (9-B)